Protein
DNA-directed RNA polymerase I subunit RPA1
Organism
Trypanosoma brucei brucei
Function
DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic core component of RNA polymerase I which synthesizes ribosomal RNA precursors. Forms the polymerase active center together with the second largest subunit. A single stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol I. A bridging helix emanates from RPA1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol I by acting as a ratchet that moves the RNA-DNA hybrid through the active site by switching from straight to bent conformations at each step of nucleotide addition (By similarity).
Similarity
Belongs to the RNA polymerase beta' chain family.
Sequence
MSGIAFVEVRTRAGQEDRSAPWRPVVRNGENHATFYDTRMGNFDANPFPPQTCQTCAASLTGKYGNERCHGHFGFVGMPRIRPGSAHSDSDRLVVLNPHLAMDADRLFRAKCFFCHKFRAPTFDVERFRQALVLADHGLPGDALHLLDTVPTAKGHDAMLNHRRMANEEIVNDVSILQSYVDRILRQRASGCSEEDAKARVTMAQKGTVDVRNDICNMAISHLRSFSGPCSHCTAISPTFLKRGGIIFFLFRKSNLVTNIAKGFLTQQEVSEWEAVNRLHGRTGTYFDGRQMLFHMKNLFAKEQAILGLLYPNLGEPSVFTKTNKVVPASERYKLFFLDRILVPPLPLRLSSGVRVNDNGLIIPDEQTRALSDILGFVEQIECFHTLSANSTNGRSFITDAQRAVNESNLRNLQQKVDEFYAEIVNSFAKKEGLFRMNMMGKRVNQACRSVISPDPFVEPNEVLLPRPLARALSFPEQVTCFAPARMNLLKHCVVNGPRKYPGATHIELRHANGEIRSVDLNVPEQTRRQHAARFFAMAQSGVTLIVYRHILNGDRVIFNRQPTLHKPSMMGYRVKVLSGSKTIRFHYVNGNSFNADFDGDEMNVHVPQSIETRAEVETLMDANINYLVPTSGRPIRGLIQDHVAAGVLVTLRDKFFDHSTFVQLVYNGVGPYIQENVGITLAELIPIPAILMPRPMWTGKQLISVMVRFSSGLSAASDCGREIEGGITLKGTSQIQPSAFDRIPAGSCDAVRAKSGAVVDSTVMFANSELITGFMCKKQLGASNMSAPHHVYELYGPHRTGQLFAAFGRVLLLALRKEGLSLAMDDMFLVDEERRCDLLRKLDDIALDVPDEEATAAPMIADYATKIQQEFVPQRMLVPFPKNHLLLMTISGAKGSNLNATQMSLQLGQQLFDGLRVKRMNSSKTLPSFFTNEKRARSFGFAMGSFASGIRPAEYTIHAMAGRDGLIDTAVKTSRSGHLQRCLIKGLESLVVHWDRTVRDSNGSVIQFMYGGDGLDPCKASTLTAWEMMKDNVVDVSKRFGGDASESVAGAEDGAAAGLKEMRNEDGKPTTEAVQNAHMEQQLSTYPLPASLDKSLSEYLCKKADFPLFRKVSTLARWDAKQQLKERLQQRRQKWVGAFEKTLADITARRRLWALCEPGEPVGLLAAQAAGEPSTQMTLNTFHTAGSTVSHVTEGIPRLRELLIYASVNKAAVVVPVTNATEEDEKVIAKMLRAGVAAKLTDCLAKVTDGAGGQSASSSMQRNLNTGFGKGYHYHVARGRTGMVITVSFLFSRSCLEELRKRMCMSPSEHRQSFTEALKNVVRLIMRSLSAVPREKESGDGSGNTGGMKGGSGRADRKRKRSGPDDGGGPLGGTFGDEIMRIEEGTDSDDGMSERSSIGGGRAGSEVSSLHSDGTDTRGIAGSDTGGPQRRRGSVESGRGDDASDSEAADPDLYARRSGSPARDAEDGGEMQDRDGTDWGGTSMQGVVGYDNFPEIHMSFTKSNFGAVIAPLSTAAAARDGVVQLHEDFFIVNAVLRTASDVIAVIPDVVDNALEAQRMPSWLPQFGSLTFTRLKDKGSGQLVFQGPGSTMRNVMSFLSLFTVGIKSIKLHQACSTDIRDMGTYFGIESGYAALYDELNKLFNRYNVDPRHLSLIADTSTHRGRWENFNFTGVISTSASPLFQMTFASSKRWLHRAVSRGMSDDLESFSSAIMVGERPRVGTASVRLSTDTAILRDVLERNFA