Jerryhuang001/TF_network huggingface dataset:
Gene: BHLHE23 (ENSG00000125533)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: No
Gene: BHLHE40 (ENSG00000134107)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Jussi Taipale) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_Transcription Factor Binding: tf co-factor binding; DNA-Binding: sequence-specific_DNA Binding_PMIDS:12297495;12397359
Annotated as a GO transcription factor: Yes
Gene: BHLHE41 (ENSG00000123095)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Tim Hughes) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Yimeng Yin) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific; Transcription Factor Binding: tf co-factor binding_DNA Binding; Other_PMIDS:12657651;15448136
Annotated as a GO transcription factor: Yes
Gene: CCDC169-SOHLH2 (ENSG00000250709)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: 100%ID - in vitro
AJ notes: Protein is a readthrough of SOHLH2 and another gene and has thus identical DBD to SOHLH2 and should thus bind just like it (if it really exists).
Disagreement on assessment: Disagree
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: No
TF-CAT classification: No
Annotated as a GO transcription factor: No
Gene: CLOCK (ENSG00000134852)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Comments: Can also bind as heterodimer with ARNTL.
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Laura Campitelli) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 comment: Can also bind as heterodimer with ARNTL (see Arttu's comment)
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_DNA Binding_PMIDS:9616112;15147242;15500444
Annotated as a GO transcription factor: Yes
PDB structure: 4H10
Gene: EPAS1 (ENSG00000116016)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: In vivo/Misc source
Notes: Only known motifs are from Transfac or HocoMoco - origin is uncertain
TRH notes: (Motif unclear - Matt changed to likely)
Reviewer 1 (Tim Hughes) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 1 comment: I can't tell where the motifs come from.  "HOMER" is not an experimental method - we need to change these entries so it is possible to trace the origin of the data.
Reviewer 1 notes: I can't tell where the motifs come from.  "HOMER" is not an experimental method - we need to change these entries so it is possible to trace the origin of the data.
Reviewer 2 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_Transcription Factor Binding: tf co-factor binding; DNA-Binding: sequence-specific_Co-activation; DNA Binding_PMIDS:15190133
Annotated as a GO transcription factor: Yes
PDB structure: 4ZPK
Gene: FERD3L (ENSG00000146618)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Laura Campitelli) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: No
Gene: FIGLA (ENSG00000183733)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_DNA Binding; Transactivation_PMIDS:9362457;15044608
Annotated as a GO transcription factor: No
Gene: HAND1 (ENSG00000113196)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 2 Obligate heteromer
Motif status: In vivo/Misc source
Notes: Only known motifs are from Transfac or HocoMoco - origin is uncertain
Comments: Obligate heteromer (PMID: 10611232).
TRH notes: Literature indicates obligate heterodimer
Reviewer 1 (Jussi Taipale) assessment: Likely to be sequence specific TF; binding: 2 Obligate heteromer
Reviewer 1 notes: check amino-acids required for binding; could be heteromer
Reviewer 2 (Pratyush Das) assessment: Likely to be sequence specific TF; binding: 2 Obligate heteromer
Reviewer 2 comment: PMID: 10611232
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_DNA Binding_PMIDS:7791788;11802795;16043483;7671815;15509787;16043483;10611232;16043483
Annotated as a GO transcription factor: Yes
Gene: HAND2 (ENSG00000164107)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_Transcription Factor Binding: tf co-factor binding; DNA-Binding: sequence-specific_TF PPI; Transactivation_PMIDS:11812799;12392994
Annotated as a GO transcription factor: Yes
Gene: HELT (ENSG00000187821)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Inferred motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Comments: Can form homodimers or heterodimers with HEY2 and HES5, suggesting also that the HELT homodimer is dependent of a additional Orange domain while the HEY2 heterodimer requires just the DBD (PMID: 14764602).
Reviewer 1 (Arttu Jolma) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
Reviewer 1 comment: PMID: 14764602 shows that it can form homodimers or heterodimers with HEY2 and HES5; suggesting also that the HELT homodimer is dependent of a additional Orange domain while the HEY2 heterodimer requires just the DBD
Reviewer 2 (Pratyush Das) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_DNA Binding; Transactivation_PMIDS:14764602;15071116
Annotated as a GO transcription factor: Yes
Gene: HES1 (ENSG00000114315)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Matt Weirauch) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: Yes
Gene: HES2 (ENSG00000069812)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 1 comment: Likely also binds as a heterodimer with other bHLH factors 
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_DNA Binding_PMIDS:8354270
Annotated as a GO transcription factor: No
Gene: HES3 (ENSG00000173673)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Inferred motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
AJ notes: "Likely to be a sequence specific TF" - Disagreement is due to inferred motif being classified as "Has known motif", Protein is
Disagreement on assessment: Disagree
Reviewer 1 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 1 comment: Inferred motif from HES1 (50% DBD Identity)
Reviewer 1 notes: Missing motif logos/info 
Reviewer 2 (Laura Campitelli) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_DNA Binding; Transactivation_PMIDS:10858455
Annotated as a GO transcription factor: No
Gene: HES4 (ENSG00000188290)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Inferred motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
AJ notes: "Likely to be a sequence specific TF" - Disagreement is due to inferred motif being classified as "Has known motif", Protein is
Disagreement on assessment: Disagree
Reviewer 1 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 1 comment: Indirect motif has 88% DBD Identity 
Reviewer 2 (Pratyush Das) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: No
Gene: HES5 (ENSG00000197921)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Yimeng Yin) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_TF PPI_PMIDS:15156153
Annotated as a GO transcription factor: Yes
Gene: HES6 (ENSG00000144485)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene Candidate_Transcription Factor Binding: tf co-factor binding_TF PPI_PMIDS:10851137;10976052
Annotated as a GO transcription factor: Yes
Gene: HES7 (ENSG00000179111)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Comments: Also forms heterodimers.
Reviewer 1 (Yimeng Yin) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 comment: also forms heterodimers
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene Candidate__Other_PMIDS:11260262;12783854
Annotated as a GO transcription factor: No
Gene: HEY1 (ENSG00000164683)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Laura Campitelli) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene Candidate_Transcription Factor Binding: tf co-factor binding_Transactivation_PMIDS:16199874
Annotated as a GO transcription factor: Yes
Gene: HEY2 (ENSG00000135547)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Tim Hughes) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Yimeng Yin) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: Yes
Gene: HEYL (ENSG00000163909)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Inferred motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
AJ notes: "Likely to be a sequence specific TF"  Protein sequence is almost identical to HEY1 and HEY2 and should bind as homodimer like them
Disagreement on binding: Disagree
Reviewer 1 (Jussi Taipale) assessment: Likely to be sequence specific TF; binding: 2 Obligate heteromer
Reviewer 1 notes: may be an obligate heterodimer; check for domains and residues required for DNA binding
Reviewer 2 (Yimeng Yin) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: Yes
Gene: HIF1A (ENSG00000100644)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 2 Obligate heteromer
Motif status: In vivo/Misc source
Notes: Only known motifs are from Transfac or HocoMoco - origin is uncertain
Comments: Binds as obligate heteromer with ARNT (PMID: 9027737).
TRH notes: Binds only with ARNT
Reviewer 1 (Matt Weirauch) assessment: Has known motif; binding: 2 Obligate heteromer
Reviewer 1 comment: obligate heteomer evidence: 9027737
Reviewer 1 notes: Yes - somewhat interesting case.  Has a (weak) HLH domain.  But; I cant find any great evidence that it can bind DNA on its own.  Sounds like it can only do so with ARNT.
Reviewer 2 (Yimeng Yin) assessment: Has known motif; binding: 2 Obligate heteromer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_Transactivation_PMIDS:12133832;15111179;15906272
Annotated as a GO transcription factor: Yes
PDB structure: 4ZPR
Gene: HIF3A (ENSG00000124440)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Inferred motif
Binding mode: 2 Obligate heteromer
Motif status: In vivo/Misc source
Comments: Binds DNA as a heterodimer with ARNT and ARNT2; reviewed in (PMID: 24099156).
TRH notes: Obligate heterodimer
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 2 Obligate heteromer
Reviewer 1 comment: Binds DNA as a heterodimer with ARNT and ARNT2; reviewed in PMID: 24099156
Reviewer 1 notes: bHLH domain is present in at least the transcript ENST00000300862.7 but it is missing from the annotations. Transfac model is not a bHLH target site
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 2 Obligate heteromer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: Yes
Gene: ID1 (ENSG00000125968)
DNA-binding domain: bHLH
Is a transcription factor: No
TF assessment: Unlikely to be sequence specific TF
Binding mode: 4 Not a DNA binding protein
Motif status: No motif
Comments: ID bHLH proteins lack the basic region and should not be able to bind DNA. The HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
AJ notes: "5 - not a DNA binding protein" ID bHLH proteins miss the basic region and should not be able to bind DNA, the HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
Disagreement on assessment: Disagree
Reviewer 1 (Laura Campitelli) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Yimeng Yin) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene Candidate_Transcription Factor Binding: tf co-factor binding_Other_PMIDS:2156629;11234019
Annotated as a GO transcription factor: Yes
Gene: ID2 (ENSG00000115738)
DNA-binding domain: bHLH
Is a transcription factor: No
TF assessment: Unlikely to be sequence specific TF
Binding mode: 4 Not a DNA binding protein
Motif status: No motif
Comments: ID bHLH proteins lack the basic region and should not be able to bind DNA. The HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
AJ notes: "5 - not a DNA binding protein" ID bHLH proteins miss the basic region and should not be able to bind DNA, the HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
Reviewer 1 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 1 comment: bHLH domain is missing the basic region (up to position 14 of the Pfam model). 
Reviewer 2 (Yimeng Yin) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene Candidate__DNA Binding_PMIDS:1922066;7565756
Annotated as a GO transcription factor: Yes
Gene: ID3 (ENSG00000117318)
DNA-binding domain: bHLH
Is a transcription factor: No
TF assessment: Unlikely to be sequence specific TF
Binding mode: 4 Not a DNA binding protein
Motif status: No motif
Comments: ID bHLH proteins lack the basic region and should not be able to bind DNA. The HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
AJ notes: "5 - not a DNA binding protein" ID bHLH proteins miss the basic region and should not be able to bind DNA, the HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
Disagreement on assessment: Disagree
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 1 comment: Protein is supposed to lack the basic region that bHLH proteins use to bind DNA; however it binds DNA based on PBM
Reviewer 1 notes: Protein is supposed to lack the basic region that bHLH proteins use to bind DNA; however it binds DNA based on PBM
Reviewer 2 (Pratyush Das) assessment: Likely to be sequence specific TF; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene Candidate_Transcription Factor Binding: tf co-factor binding_Other_PMIDS:15016815
Annotated as a GO transcription factor: Yes
Gene: ID4 (ENSG00000172201)
DNA-binding domain: bHLH
Is a transcription factor: No
TF assessment: Unlikely to be sequence specific TF
Binding mode: 4 Not a DNA binding protein
Motif status: No motif
Comments: ID bHLH proteins lack the basic region and should not be able to bind DNA. The HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
AJ notes: "5 - not a DNA binding protein" ID bHLH proteins miss the basic region and should not be able to bind DNA, the HT-SELEX motif for ID4 is likely by a co-precipitated protein or it is a contamination
Disagreement on assessment: Disagree
Disagreement on binding: Disagree
Reviewer 1 (Sam Lambert) assessment: Has known motif; binding: 2 Obligate heteromer
Reviewer 1 comment: ID bHLH proteins are not canonically thought to have DNA-binding activity. It is possible IFD4 motif the result of being expressed in human cells and pulling-down other bHLH TFs (A. Jolma; personal communication).  
Reviewer 2 (Pratyush Das) assessment: Unlikely to be sequence specific TF; binding: 4 Not a DNA binding protein
Reviewer 2 comment: It lacks DNA binding ability but has motif from SELEX
Reviewer 2 notes: needs a revisit
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene Candidate__Transactivation_PMIDS:7665172;8139914
Annotated as a GO transcription factor: No
Gene: LYL1 (ENSG00000104903)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Inferred motif
Binding mode: 2 Obligate heteromer
Motif status: In vivo/Misc source
Comments: TAL1, TAL2 and LYL are very similar and have a basic region with a bulky tryptophan inserting into the cluster of the basic residues. Binds DNA as a heterodimer with TCF3 (PDB:2YPB and PDB:2YPA).
AJ notes: "Likely to be sequence specific TF" "2 Obligate heteromer" TAL1, TAL2 and LYL are very similar and have a basic region with a bulky tryptophan inserting into the cluster of the basic residues, yet at least TAL1 binds DNA well as a heterodimer with TCF3. The motifs seem like in vivo motifs except possibly for a one transfac motif. Is known to bind DNA as heterodimer with TCF3 PDB:2YPB and PDB:2YPA
Reviewer 1 (Matt Weirauch) assessment: Likely to be sequence specific TF; binding: 2 Obligate heteromer
Reviewer 1 comment: Evidence seems to suggest it is an obligate heteromer.  Tests on both PBMs and HT-SELEX yielded no motif.
Reviewer 2 (Pratyush Das) assessment: Likely to be sequence specific TF; binding: 2 Obligate heteromer
Reviewer 2 comment: PMID: 22772404
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: Yes
Gene: MAX (ENSG00000125952)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Jussi Taipale) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Pratyush Das) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific_DNA Binding_PMIDS:8265351
Annotated as a GO transcription factor: Yes
PDB structure: 1AN2
Gene: MESP1 (ENSG00000166823)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: No
Annotated as a GO transcription factor: Yes
Gene: MESP2 (ENSG00000188095)
DNA-binding domain: bHLH
Is a transcription factor: Yes
TF assessment: Known motif
Binding mode: 1 Monomer or homomultimer
Motif status: High-throughput in vitro
TRH notes: Seems straightforward
Reviewer 1 (Arttu Jolma) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 (Sam Lambert) assessment: Has known motif; binding: 1 Monomer or homomultimer
Reviewer 2 notes: Missing motif logos/info 
CisBP considers it a TF: Yes
TFclass considers it a TF: Yes
TF-CAT classification: TF Gene_DNA-Binding: sequence-specific; Transcription Factor Binding: tf co-factor binding_Co-activation_PMIDS:16728472
Annotated as a GO transcription factor: No