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Overview

Uniprot IDO95602
Protein NameDNA-directed RNA polymerase I subunit RPA1
Gene NamePOLR1A
OrganismHomo sapiens

Kla Sites from experimental identification

Position Flanking peptide
1360 SIKKKNNKASAFRNV

Function

Catalytic core component of RNA polymerase I (Pol I), a DNA-dependent RNA polymerase which synthesizes ribosomal RNA precursors using the four ribonucleoside triphosphates as substrates. Transcribes 47S pre-rRNAs from multicopy rRNA gene clusters, giving rise to 5.8S, 18S and 28S ribosomal RNAs (PubMed:11250903, PubMed:11283244, PubMed:16858408, PubMed:34671025, PubMed:34887565, PubMed:36271492). Pol I-mediated transcription cycle proceeds through transcription initiation, transcription elongation and transcription termination stages. During transcription initiation, Pol I pre-initiation complex (PIC) is recruited by the selectivity factor 1 (SL1/TIF-IB) complex bound to the core promoter that precedes an rDNA repeat unit. The PIC assembly bends the promoter favoring the formation of the transcription bubble and promoter escape. Once the polymerase has escaped from the promoter it enters the elongation phase during which RNA is actively polymerized, based on complementarity with the template DNA strand. Highly processive, assembles in structures referred to as 'Miller trees' where many elongating Pol I complexes queue and transcribe the same rDNA coding regions. At terminator sequences downstream of the rDNA gene, PTRF interacts with Pol I and halts Pol I transcription leading to the release of the RNA transcript and polymerase from the DNA (PubMed:11250903, PubMed:11283244, PubMed:16858408, PubMed:34671025, PubMed:34887565, PubMed:36271492). Forms Pol I active center together with the second largest subunit POLR1B/RPA2. Appends one nucleotide at a time to the 3' end of the nascent RNA, with POLR1A/RPA1 contributing a Mg(2+)-coordinating DxDGD motif, and POLR1B/RPA2 participating in the coordination of a second Mg(2+) ion and providing lysine residues believed to facilitate Watson-Crick base pairing between the incoming nucleotide and the template base. Typically, Mg(2+) ions direct a 5' nucleoside triphosphate to form a phosphodiester bond with the 3' hydroxyl of the preceding nucleotide of the nascent RNA, with the elimination of pyrophosphate. Has proofreading activity: Pauses and backtracks to allow the cleavage of a missincorporated nucleotide via POLR1H/RPA12. High Pol I processivity is associated with decreased transcription fidelity (By similarity) (PubMed:11250903, PubMed:11283244, PubMed:16858408, PubMed:34671025, PubMed:34887565, PubMed:36271492)

Protein Sequence

10 MLISKNMPWR 20 RLQGISFGMY 30 SAEELKKLSV 40 KSITNPRYLD 50 SLGNPSANGL 60 YDLALGPADS 70 KEVCSTCVQD 80 FSNCSGHLGH 90 IELPLTVYNP 100 LLFDKLYLLL 110 RGSCLNCHML 120 TCPRAVIHLL 130 LCQLRVLEVG 140 ALQAVYELER 150 ILNRFLEENP 160 DPSASEIREE 170 LEQYTTEIVQ 180 NNLLGSQGAH 190 VKNVCESKSK 200 LIALFWKAHM 210 NAKRCPHCKT 220 GRSVVRKEHN 230 SKLTITFPAM 240 VHRTAGQKDS 250 EPLGIEEAQI 260 GKRGYLTPTS 270 AREHLSALWK 280 NEGFFLNYLF 290 SGMDDDGMES 300 RFNPSVFFLD 310 FLVVPPSRYR 320 PVSRLGDQMF 330 TNGQTVNLQA 340 VMKDVVLIRK 350 LLALMAQEQK 360 LPEEVATPTT 370 DEEKDSLIAI 380 DRSFLSTLPG 390 QSLIDKLYNI 400 WIRLQSHVNI 410 VFDSEMDKLM 420 MDKYPGIRQI 430 LEKKEGLFRK 440 HMMGKRVDYA 450 ARSVICPDMY 460 INTNEIGIPM 470 VFATKLTYPQ 480 PVTPWNVQEL 490 RQAVINGPNV 500 HPGASMVINE 510 DGSRTALSAV 520 DMTQREAVAK 530 QLLTPATGAP 540 KPQGTKIVCR 550 HVKNGDILLL 560 NRQPTLHRPS 570 IQAHRARILP 580 EEKVLRLHYA 590 NCKAYNADFD 600 GDEMNAHFPQ 610 SELGRAEAYV 620 LACTDQQYLV 630 PKDGQPLAGL 640 IQDHMVSGAS 650 MTTRGCFFTR 660 EHYMELVYRG 670 LTDKVGRVKL 680 LSPSILKPFP 690 LWTGKQVVST 700 LLINIIPEDH 710 IPLNLSGKAK 720 ITGKAWVKET 730 PRSVPGFNPD 740 SMCESQVIIR 750 EGELLCGVLD 760 KAHYGSSAYG 770 LVHCCYEIYG 780 GETSGKVLTC 790 LARLFTAYLQ 800 LYRGFTLGVE 810 DILVKPKADV 820 KRQRIIEEST 830 HCGPQAVRAA 840 LNLPEAASYD 850 EVRGKWQDAH 860 LGKDQRDFNM 870 IDLKFKEEVN 880 HYSNEINKAC 890 MPFGLHRQFP 900 ENSLQMMVQS 910 GAKGSTVNTM 920 QISCLLGQIE 930 LEGRRPPLMA 940 SGKSLPCFEP 950 YEFTPRAGGF 960 VTGRFLTGIK 970 PPEFFFHCMA 980 GREGLVDTAV 990 KTSRSGYLQR 1000 CIIKHLEGLV 1010 VQYDLTVRDS 1020 DGSVVQFLYG 1030 EDGLDIPKTQ 1040 FLQPKQFPFL 1050 ASNYEVIMKS 1060 QHLHEVLSRA 1070 DPKKALHHFR 1080 AIKKWQSKHP 1090 NTLLRRGAFL 1100 SYSQKIQEAV 1110 KALKLESENR 1120 NGRSPGTQEM 1130 LRMWYELDEE 1140 SRRKYQKKAA 1150 ACPDPSLSVW 1160 RPDIYFASVS 1170 ETFETKVDDY 1180 SQEWAAQTEK 1190 SYEKSELSLD 1200 RLRTLLQLKW 1210 QRSLCEPGEA 1220 VGLLAAQSIG 1230 EPSTQMTLNT 1240 FHFAGRGEMN 1250 VTLGIPRLRE 1260 ILMVASANIK 1270 TPMMSVPVLN 1280 TKKALKRVKS 1290 LKKQLTRVCL 1300 GEVLQKIDVQ 1310 ESFCMEEKQN 1320 KFQVYQLRFQ 1330 FLPHAYYQQE 1340 KCLRPEDILR 1350 FMETRFFKLL 1360 MESIKKKNNK 1370 ASAFRNVNTR 1380 RATQRDLDNA 1390 GELGRSRGEQ 1400 EGDEEEEGHI 1410 VDAEAEEGDA 1420 DASDAKRKEK 1430 QEEEVDYESE 1440 EEEEREGEEN 1450 DDEDMQEERN 1460 PHREGARKTQ 1470 EQDEEVGLGT 1480 EEDPSLPALL 1490 TQPRKPTHSQ 1500 EPQGPEAMER 1510 RVQAVREIHP 1520 FIDDYQYDTE 1530 ESLWCQVTVK 1540 LPLMKINFDM 1550 SSLVVSLAHG 1560 AVIYATKGIT 1570 RCLLNETTNN 1580 KNEKELVLNT 1590 EGINLPELFK 1600 YAEVLDLRRL 1610 YSNDIHAIAN 1620 TYGIEAALRV 1630 IEKEIKDVFA 1640 VYGIAVDPRH 1650 LSLVADYMCF 1660 EGVYKPLNRF 1670 GIRSNSSPLQ 1680 QMTFETSFQF 1690 LKQATMLGSH 1700 DELRSPSACL 1710 VVGKVVRGGT 1720 GLFELKQPLR

Gene Ontology

Classification GO ID Description
Cellular Component GO:0000785 chromatin
Cellular Component GO:0005694 chromosome
Cellular Component GO:0001650 fibrillar center
Cellular Component GO:0005654 nucleoplasm
Cellular Component GO:0005634 nucleus
Cellular Component GO:0005736 RNA polymerase I complex
Molecular Function GO:0003682 chromatin binding
Molecular Function GO:0003677 DNA binding
Molecular Function GO:0003899 DNA-directed RNA polymerase activity
Molecular Function GO:0071667 DNA/RNA hybrid binding
Molecular Function GO:0000287 magnesium ion binding
Molecular Function GO:0008270 zinc ion binding
Biological Process GO:1904750 negative regulation of protein localization to nucleolus
Biological Process GO:0042790 nucleolar large rRNA transcription by RNA polymerase I
Biological Process GO:0006363 termination of RNA polymerase I transcription
Biological Process GO:0006360 transcription by RNA polymerase I
Biological Process GO:0006362 transcription elongation by RNA polymerase I
Biological Process GO:0006361 transcription initiation at RNA polymerase I promoter

Reference

PMID: N/A