Protein: DNA-directed RNA polymerases IV and V subunit 2 (EC 2.7.7.6) (DNA-directed RNA polymerase D subunit 2a) (AtNRPD2a) (Nuclear RNA polymerase D 2a) (Nuclear RNA polymerase E 2) (Protein DEFECTIVE IN MERISTEM SILENCING 2) (Protein DEFECTIVE IN RNA-DIRECTED DNA METHYLATION 2) (RNA polymerase IV subunit 2a) (POL IV 2a) (Q9LK40)
Organism: Arabidopsis thaliana (Mouse-ear cress)
Function: DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Second largest component of RNA polymerases IV and V which mediate short-interfering RNAs (siRNA) accumulation and subsequent RNA-directed DNA methylation-dependent (RdDM) transcriptional gene silencing (TGS) of endogenous repeated sequences, including transposable elements. Proposed to contribute to the polymerase catalytic activity and forms the polymerase active center together with the largest subunit. Also required for full erasure of methylation when the RNA trigger is withdrawn. Required for intercellular RNA interference (RNAi) leading to systemic post-transcriptional gene silencing. Involved in the maintenance of post-transcriptional RNA silencing. During interphase, mediates siRNA-independent heterochromatin association and methylation into chromocenters and condensation and cytosine methylation at pericentromeric major repeats. Required for complete maintenance of the 35S promoter homology-dependent TGS in transgenic plants and for the initial establishment of DNA methylation.
Subcellular location: Nucleus {ECO:0000269|PubMed:15766525, ECO:0000269|PubMed:16140984, ECO:0000269|PubMed:16839878}. Note=Concentrated in numerous distinct foci around chromocenters.
Interaction partners:
- DNA-directed RNA polymerases II, IV and V subunit 10
- DNA-directed RNA polymerase V subunit 1
- DNA-directed RNA polymerases II, IV and V subunit 3
- DNA-directed RNA polymerases II, IV and V subunit 12
- DNA-directed RNA polymerase IV subunit 1
- DNA-directed RNA polymerases II, IV and V subunit 6A
- DNA-directed RNA polymerases II, IV and V subunit 8B
- DNA-directed RNA polymerases II, IV and V subunit 11
- DNA-directed RNA polymerases II, IV and V subunit 9A
- DNA-directed RNA polymerases II and IV subunit 5A
Sequence:
MPDMDIDVKDLEEFEATTGEINLSELGEGFLQSFCKKAATSFFDKYGLISHQLNSYNYFIEHGLQNVFQSFGEMLVEPSFDVVKKKDNDWRYATVKFGEVTVEKPTFFSDDKELEFLPWHARLQNMTYSARIKVNVQVEVFKNTVVKSDKFKTGQDNYVEKKILDVKKQDILIGSIPVMVKSILCKTSEKGKENCKKGDCAFDQGGYFVIKGAEKVFIAQEQMCTKRLWISNSPWTVSFRSENKRNRFIVRLSENEKAEDYKRREKVLTVYFLSTEIPVWLLFFALGVSSDKEAMDLIAFDGDDASITNSLIASIHVADAVCEAFRCGNNALTYVEQQIKSTKFPPAESVDECLHLYLFPGLQSLKKKARFLGYMVKCLLNSYAGKRKCENRDSFRNKRIELAGELLEREIRVHLAHARRKMTRAMQKHLSGDGDLKPIEHYLDASVITNGLSRAFSTGAWSHPFRKMERVSGVVANLGRANPLQTLIDLRRTRQQVLYTGKVGDARYPHPSHWGRVCFLSTPDGENCGLVKNMSLLGLVSTQSLESVVEKLFACGMEELMDDTCTPLFGKHKVLLNGDWVGLCADSESFVAELKSRRRQSELPREMEIKRDKDDNEVRIFTDAGRLLRPLLVVENLQKLKQEKPSQYPFDHLLDHGILELIGIEEEEDCNTAWGIKQLLKEPKIYTHCELDLSFLLGVSCAVVPFANHDHGRRVLYQSQKHCQQAIGFSSTNPNIRCDTLSQQLFYPQKPLFKTLASECLKKEVLFNGQNAIVAVNVHLGYNQEDSIVMNKASLERGMFRSEQIRSYKAEVDAKDSEKRKKMDELVQFGKTHSKIGKVDSLEDDGFPFIGANMSTGDIVIGRCTESGADHSIKLKHTERGIVQKVVLSSNDEGKNFAAVSLRQVRSPCLGDKFSSMHGQKGVLGYLEEQQNFPFTIQGIVPDIVINPHAFPSRQTPGQLLEAALSKGIACPIQKEGSSAAYTKLTRHATPFSTPGVTEITEQLHRAGFSRWGNERVYNGRSGEMMRSMIFMGPTFYQRLVHMSEDKVKFRNTGPVHPLTRQPVADRKRFGGIKFGEMERDCLIAHGASANLHERLFTLSDSSQMHICRKCKTYANVIERTPSSGRKIRGPYCRVCVSSDHVVRVYVPYGAKLLCQELFSMGITLNFDTKLC