Human protein: transcription initiation factor IIB
Human protein sequence: MASTSRLDALPRVTCPNHPDAILVEDYRAGDMICPECGLVVGDRVIDVGSEWRTFSNDKATKDPSRVGDSQNPLLSDGDLSTMIGKGTGAASFDEFGNSKYQNRRTMSSSDRAMMNAFKEITTMADRINLPRNIVDRTNNLFKQVYEQKSLKGRANDAIASACLYIACRQEGVPRTFKEICAVSRISKKEIGRCFKLILKALETSVDLITTGDFMSRFCSNLCLPKQVQMAATHIARKAVELDLVPGRSPISVAAAAIYMASQASAEKRTQKEIGDIAGVADVTIRQSYRLIYPRAPDLFPTDFKFDTPVDKLPQL

HIV protein: nucleocapsid
Interaction type: enhances
Description: HIV-1 Nucleocapsid has been shown to bind to the HIV-1 LTR promoter and enhance NF-kappaB, Sp1, and TFIIB-induced HIV-1 LTR-directed RNA transcription
HIV protein sequence: MQRGNFRNQRKIVKCFNCGKEGHTARNCRAPRKKGCWKCGKEGHQMKDCTERQAN

HIV protein: Vpr
Interaction type: binds
Description: Specific binding of HIV-1 Vpr (amino acids 15-35) to TFIIB (amino acids 52-55) causes a conformational change in TFIIB and is correlated with the ability of Vpr to stimulate transcription through the glucocorticoid receptor pathway
HIV protein sequence: MEQAPEDQGPQREPHNEWTLELLEELKNEAVRHFPRIWLHGLGQHIYETYGDTWAGVEAIIRILQQLLFIHFRIGCRHSRIGVTRQRRARNGASRS

HIV protein: Tat
Interaction type: recruits
Description: Binding of HIV-1 Tat to p300 induces a conformational change in the CBP/p300 complex such that it can acquire and bind better to transcription factors such as TBP and TFIIB, indicating Tat helps CBP/p300 recruit new partners to the transcription machinery
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: inhibited by
Description: Overexpression of TFIIB inhibits HIV-1 Tat-mediated transactivation of the HIV-1 LTR promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: HIV-1 Tat interacts with a cellular protein, TAP (Tat-associated protein), that functions as a co-activator and bridges Tat to the general transcription machinery via TFIIB
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: Transactivation of the HIV-1 LTR by HIV-1 Tat and the cellular cofactor Tat-SF1 is mediated by basal transcription factors, including TFIIB
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: HIV-1 Tat interacts with the RNA polymerase II holoenzyme complex that supports Tat-mediated transactivation of the HIV-1 LTR in vitro upon addition of TBP and TFIIB
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: The cysteine rich and core domains (amino acids 27-103) of HIV-1 Tat mediate binding to two domains of TFIIB, amino acids 27-103 in the N-terminal domain and the first direct repeat of the C-terminal domain between amino acids 148-163
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: HIV-1 Tat directly interacts with TFIIB as demonstrated by Tat-affinity column purification
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE