SIGR_STRCO
ID SIGR_STRCO Reviewed; 227 AA.
AC Q7AKG9; O87834;
DT 16-OCT-2013, integrated into UniProtKB/Swiss-Prot.
DT 16-MAY-2012, sequence version 1.
DT 25-MAY-2022, entry version 59.
DE RecName: Full=ECF RNA polymerase sigma factor SigR;
DE Short=ECF sigma factor SigR;
DE AltName: Full=Alternative RNA polymerase sigma factor SigR;
DE AltName: Full=RNA polymerase sigma-R factor;
DE Short=Sigma-R factor;
GN Name=sigR; OrderedLocusNames=SCO5216;
OS Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145).
OC Bacteria; Actinobacteria; Streptomycetales; Streptomycetaceae;
OC Streptomyces; Streptomyces albidoflavus group.
OX NCBI_TaxID=100226;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 5-24, FUNCTION AS A
RP SIGMA FACTOR, INDUCTION, AUTOREGULATION, AND DISRUPTION PHENOTYPE.
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=9755177; DOI=10.1093/emboj/17.19.5776;
RA Paget M.S., Kang J.G., Roe J.H., Buttner M.J.;
RT "sigmaR, an RNA polymerase sigma factor that modulates expression of the
RT thioredoxin system in response to oxidative stress in Streptomyces
RT coelicolor A3(2).";
RL EMBO J. 17:5776-5782(1998).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=12000953; DOI=10.1038/417141a;
RA Bentley S.D., Chater K.F., Cerdeno-Tarraga A.-M., Challis G.L.,
RA Thomson N.R., James K.D., Harris D.E., Quail M.A., Kieser H., Harper D.,
RA Bateman A., Brown S., Chandra G., Chen C.W., Collins M., Cronin A.,
RA Fraser A., Goble A., Hidalgo J., Hornsby T., Howarth S., Huang C.-H.,
RA Kieser T., Larke L., Murphy L.D., Oliver K., O'Neil S., Rabbinowitsch E.,
RA Rajandream M.A., Rutherford K.M., Rutter S., Seeger K., Saunders D.,
RA Sharp S., Squares R., Squares S., Taylor K., Warren T., Wietzorrek A.,
RA Woodward J.R., Barrell B.G., Parkhill J., Hopwood D.A.;
RT "Complete genome sequence of the model actinomycete Streptomyces coelicolor
RT A3(2).";
RL Nature 417:141-147(2002).
RN [3]
RP FUNCTION AS A SIGMA-FACTOR, INTERACTION WITH RSRA, AND SUBUNIT.
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=10428967; DOI=10.1093/emboj/18.15.4292;
RA Kang J.G., Paget M.S.B., Seok Y.J., Hahn M.Y., Bae J.B., Hahn J.S.;
RT "RsrA, an anti-sigma factor regulated by redox change.";
RL EMBO J. 18:4292-4298(1999).
RN [4]
RP FUNCTION, SUBUNIT, AND REGULON.
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=11737643; DOI=10.1046/j.1365-2958.2001.02675.x;
RA Paget M.S.B., Molle V., Cohen G., Aharonowitz Y., Buttner M.J.;
RT "Defining the disulphide stress response in Streptomyces coelicolor A3(2):
RT identification of the sigmaR regulon.";
RL Mol. Microbiol. 42:1007-1020(2001).
RN [5]
RP FUNCTION AS A SIGMA FACTOR, AND INTERACTION WITH RSRA.
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=14529630; DOI=10.1016/j.jmb.2003.08.038;
RA Li W., Bottrill A.R., Bibb M.J., Buttner M.J., Paget M.S., Kleanthous C.;
RT "The role of zinc in the disulphide stress-regulated anti-sigma factor RsrA
RT from Streptomyces coelicolor.";
RL J. Mol. Biol. 333:461-472(2003).
RN [6]
RP REGULON, INDUCTION, AND DISRUPTION PHENOTYPE.
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=18430082; DOI=10.1111/j.1365-2958.2008.06191.x;
RA Park J.H., Roe J.H.;
RT "Mycothiol regulates and is regulated by a thiol-specific antisigma factor
RT RsrA and sigma(R) in Streptomyces coelicolor.";
RL Mol. Microbiol. 68:861-870(2008).
RN [7]
RP INDUCTION, ALTERNATIVE INITIATION (SIGR PRIME), AND PROBABLE CLEAVAGE.
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=19682253; DOI=10.1111/j.1365-2958.2009.06824.x;
RA Kim M.S., Hahn M.Y., Cho Y., Cho S.N., Roe J.H.;
RT "Positive and negative feedback regulatory loops of thiol-oxidative stress
RT response mediated by an unstable isoform of sigmaR in actinomycetes.";
RL Mol. Microbiol. 73:815-825(2009).
RN [8]
RP REGULON.
RX PubMed=22651816; DOI=10.1111/j.1365-2958.2012.08115.x;
RA Kim M.S., Dufour Y.S., Yoo J.S., Cho Y.B., Park J.H., Nam G.B., Kim H.M.,
RA Lee K.L., Donohue T.J., Roe J.H.;
RT "Conservation of thiol-oxidative stress responses regulated by SigR
RT orthologues in actinomycetes.";
RL Mol. Microbiol. 85:326-344(2012).
RN [9]
RP X-RAY CRYSTALLOGRAPHY (2.38 ANGSTROMS) OF 23-109, AND INTERACTION WITH
RP RSRA.
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=12381317; DOI=10.1016/s0022-2836(02)00948-8;
RA Li W., Stevenson C.E., Burton N., Jakimowicz P., Paget M.S., Buttner M.J.,
RA Lawson D.M., Kleanthous C.;
RT "Identification and structure of the anti-sigma factor-binding domain of
RT the disulphide-stress regulated sigma factor sigma(R) from Streptomyces
RT coelicolor.";
RL J. Mol. Biol. 323:225-236(2002).
CC -!- FUNCTION: Sigma factors are initiation factors that promote the
CC attachment of RNA polymerase to specific initiation sites and are then
CC released. Extracytoplasmic function (ECF) sigma factors are held in an
CC inactive form by an anti-sigma factor (RsrA) until released. Responds
CC to thiol-oxidative stress, involved in regulation of about 30 genes and
CC operons, including the thioredoxin system (trxB-trxA, trxC), ribosomal
CC protein L31, RNA polymerase-binding protein RbpA and mycothiol (MSH)
CC biosynthetic (mshA) and recycling genes (mca). In conjunction with its
CC cognate anti-sigma factor RsrA may sense the intracellular level of
CC reduced MSH. {ECO:0000269|PubMed:10428967, ECO:0000269|PubMed:11737643,
CC ECO:0000269|PubMed:14529630, ECO:0000269|PubMed:9755177}.
CC -!- SUBUNIT: Interacts transiently with the RNA polymerase catalytic core
CC formed by RpoA, RpoB, RpoC and RpoZ (2 alpha, 1 beta, 1 beta' and 1
CC omega subunit) to form the RNA polymerase holoenzyme that can initiate
CC transcription. Interacts with cognate anti-sigma factor RsrA under
CC reducing but not oxiding conditions, which prevents it binding to RNA
CC polymerase. Treatment with the thiol-oxidzing agent diamide inhibits
CC the interaction. {ECO:0000269|PubMed:10428967,
CC ECO:0000269|PubMed:11737643, ECO:0000269|PubMed:12381317,
CC ECO:0000269|PubMed:14529630}.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative initiation; Named isoforms=2;
CC Name=SigR;
CC IsoId=Q7AKG9-1; Sequence=Displayed;
CC Name=SigR prime;
CC IsoId=Q7AKG9-2; Sequence=VSP_053231;
CC -!- INDUCTION: Expressed from 2 promoters, 1 of which (sigRp2) positively
CC regulates its own expression. The same promoter is transiently induced
CC (about 70-fold) by the thiol-oxiding agent diamide. Also induced when
CC mycothiol is oxidized or conjugated. {ECO:0000269|PubMed:18430082,
CC ECO:0000269|PubMed:19682253, ECO:0000269|PubMed:9755177}.
CC -!- DOMAIN: The sigma-70 factor domain-2 mediates sequence-specific
CC interaction with the -10 element in promoter DNA, and plays an
CC important role in melting the double-stranded DNA and the formation of
CC the transcription bubble. The sigma-70 factor domain-2 mediates
CC interaction with the RNA polymerase subunits RpoB and RpoC (By
CC similarity). Interactions between sigma-70 factor domain-2 and anti-
CC sigma factors prevents interaction of sigma factors with the RNA
CC polymerase catalytic core (Probable). {ECO:0000250, ECO:0000305}.
CC -!- DOMAIN: The sigma-70 factor domain-4 contains a helix-turn-helix (H-T-
CC H) motif that mediates interaction with the -35 element in promoter
CC DNA. The domain also mediates interaction with the RNA polymerase
CC subunit RpoA (By similarity). {ECO:0000250}.
CC -!- PTM: SigR is present in multiple forms of different pI, suggesting
CC other unknown post-translational modifications.
CC -!- PTM: SigR prime is probably partially degraded by ClpP1-ClpP2.
CC -!- DISRUPTION PHENOTYPE: Increased sensitivity to redox-cycling compounds
CC menadione and plumbagin, and to diamide. Loss of expression of
CC mycothiol biosynthetic and recycling genes.
CC {ECO:0000269|PubMed:18430082, ECO:0000269|PubMed:9755177}.
CC -!- MISCELLANEOUS: [Isoform SigR]: Constitutively expressed major isoform,
CC not induced by diamide (at protein level), contributes about half of
CC the diamide-induced expression of the regulon.
CC -!- MISCELLANEOUS: [Isoform SigR prime]: Present in low amounts in
CC unstressed cells, strongly but transiently produced upon diamide
CC induction. Functions as a sigma factor, contributes about half of the
CC diamide-induced expression of the regulon. Unstable, half-life of about
CC 10 minutes. {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the sigma-70 factor family. ECF subfamily.
CC {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; AJ010320; CAA09088.1; -; Genomic_DNA.
DR EMBL; AL939122; CAB94601.1; -; Genomic_DNA.
DR PIR; T42015; T42015.
DR RefSeq; NP_629363.1; NC_003888.3. [Q7AKG9-1]
DR RefSeq; WP_003973756.1; NZ_VNID01000008.1.
DR PDB; 1H3L; X-ray; 2.38 A; A/B=23-109.
DR PDB; 5FGM; X-ray; 2.60 A; A=143-207.
DR PDBsum; 1H3L; -.
DR PDBsum; 5FGM; -.
DR AlphaFoldDB; Q7AKG9; -.
DR SMR; Q7AKG9; -.
DR STRING; 100226.SCO5216; -.
DR GeneID; 1100657; -.
DR KEGG; sco:SCO5216; -.
DR PATRIC; fig|100226.15.peg.5300; -.
DR eggNOG; COG1595; Bacteria.
DR HOGENOM; CLU_047691_1_1_11; -.
DR InParanoid; Q7AKG9; -.
DR OMA; NAKAWLF; -.
DR PhylomeDB; Q7AKG9; -.
DR Proteomes; UP000001973; Chromosome.
DR GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR GO; GO:0016987; F:sigma factor activity; IDA:UniProtKB.
DR GO; GO:0006352; P:DNA-templated transcription, initiation; IEA:InterPro.
DR GO; GO:0006979; P:response to oxidative stress; IDA:UniProtKB.
DR Gene3D; 1.10.10.10; -; 1.
DR InterPro; IPR039425; RNA_pol_sigma-70-like.
DR InterPro; IPR014284; RNA_pol_sigma-70_dom.
DR InterPro; IPR014293; RNA_pol_sigma70_actinobac.
DR InterPro; IPR000838; RNA_pol_sigma70_ECF_CS.
DR InterPro; IPR007627; RNA_pol_sigma70_r2.
DR InterPro; IPR013249; RNA_pol_sigma70_r4_t2.
DR InterPro; IPR013325; RNA_pol_sigma_r2.
DR InterPro; IPR013324; RNA_pol_sigma_r3/r4-like.
DR InterPro; IPR036388; WH-like_DNA-bd_sf.
DR PANTHER; PTHR43133; PTHR43133; 1.
DR Pfam; PF04542; Sigma70_r2; 1.
DR Pfam; PF08281; Sigma70_r4_2; 1.
DR SUPFAM; SSF88659; SSF88659; 1.
DR SUPFAM; SSF88946; SSF88946; 1.
DR TIGRFAMs; TIGR02947; SigH_actino; 1.
DR TIGRFAMs; TIGR02937; sigma70-ECF; 1.
DR PROSITE; PS01063; SIGMA70_ECF; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Alternative initiation; Direct protein sequencing;
KW DNA-binding; Reference proteome; Sigma factor; Transcription;
KW Transcription regulation.
FT CHAIN 1..227
FT /note="ECF RNA polymerase sigma factor SigR"
FT /id="PRO_0000423649"
FT DNA_BIND 173..192
FT /note="H-T-H motif"
FT /evidence="ECO:0000250"
FT REGION 1..33
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 43..106
FT /note="Sigma-70 factor domain-2"
FT REGION 148..198
FT /note="Sigma-70 factor domain-4"
FT MOTIF 63..66
FT /note="Polymerase core binding"
FT /evidence="ECO:0000255"
FT VAR_SEQ 1
FT /note="M -> MGSAFCPSRSSRADLDWTVLHAAKTAPIRAAGGPDRRLSSDSSETGL
FT GFTTTSEEM (in isoform SigR prime)"
FT /evidence="ECO:0000305"
FT /id="VSP_053231"
FT HELIX 29..42
FT /evidence="ECO:0007829|PDB:1H3L"
FT HELIX 44..55
FT /evidence="ECO:0007829|PDB:1H3L"
FT HELIX 58..75
FT /evidence="ECO:0007829|PDB:1H3L"
FT HELIX 76..78
FT /evidence="ECO:0007829|PDB:1H3L"
FT STRAND 81..83
FT /evidence="ECO:0007829|PDB:1H3L"
FT HELIX 85..99
FT /evidence="ECO:0007829|PDB:1H3L"
FT HELIX 148..153
FT /evidence="ECO:0007829|PDB:5FGM"
FT HELIX 157..167
FT /evidence="ECO:0007829|PDB:5FGM"
FT HELIX 173..180
FT /evidence="ECO:0007829|PDB:5FGM"
FT HELIX 184..204
FT /evidence="ECO:0007829|PDB:5FGM"
SQ SEQUENCE 227 AA; 25218 MW; AE89C2EF0ED4F366 CRC64;
MGPVTGTDAG TEHGQAEQPE GRGTGAESTA ERSARFERDA LEFLDQMYSA ALRMTRNPAD
AEDLVQETYA KAYASFHQFR EGTNLKAWLY RILTNTFINS YRKKQREPQR SAAEEIEDWQ
LARAESHMST GLRSAESQAL DHLPDSDVKQ ALQAIPEEFR IAVYLADVEG FAYKEIADIM
GTPIGTVMSR LHRGRRQLRG MLEDYARDRG LVPAGAGESN EAKGSGS
