ID   MTNA_SYNY3              Reviewed;         351 AA.
AC   P74497;
DT   15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   03-AUG-2022, entry version 131.
DE   RecName: Full=Methylthioribose-1-phosphate isomerase {ECO:0000255|HAMAP-Rule:MF_01678};
DE            Short=M1Pi {ECO:0000255|HAMAP-Rule:MF_01678};
DE            Short=MTR-1-P isomerase {ECO:0000255|HAMAP-Rule:MF_01678};
DE            EC=5.3.1.23 {ECO:0000255|HAMAP-Rule:MF_01678};
DE   AltName: Full=S-methyl-5-thioribose-1-phosphate isomerase {ECO:0000255|HAMAP-Rule:MF_01678};
GN   Name=mtnA {ECO:0000255|HAMAP-Rule:MF_01678}; OrderedLocusNames=slr1938;
OS   Synechocystis sp. (strain PCC 6803 / Kazusa).
OC   Bacteria; Cyanobacteria; Synechococcales; Merismopediaceae; Synechocystis;
OC   unclassified Synechocystis.
OX   NCBI_TaxID=1111708;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PCC 6803 / Kazusa;
RX   PubMed=8905231; DOI=10.1093/dnares/3.3.109;
RA   Kaneko T., Sato S., Kotani H., Tanaka A., Asamizu E., Nakamura Y.,
RA   Miyajima N., Hirosawa M., Sugiura M., Sasamoto S., Kimura T., Hosouchi T.,
RA   Matsuno A., Muraki A., Nakazaki N., Naruo K., Okumura S., Shimpo S.,
RA   Takeuchi C., Wada T., Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence analysis of the genome of the unicellular cyanobacterium
RT   Synechocystis sp. strain PCC6803. II. Sequence determination of the entire
RT   genome and assignment of potential protein-coding regions.";
RL   DNA Res. 3:109-136(1996).
CC   -!- FUNCTION: Catalyzes the interconversion of methylthioribose-1-phosphate
CC       (MTR-1-P) into methylthioribulose-1-phosphate (MTRu-1-P).
CC       {ECO:0000255|HAMAP-Rule:MF_01678}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=S-methyl-5-thio-alpha-D-ribose 1-phosphate = S-methyl-5-thio-
CC         D-ribulose 1-phosphate; Xref=Rhea:RHEA:19989, ChEBI:CHEBI:58533,
CC         ChEBI:CHEBI:58548; EC=5.3.1.23; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01678};
CC   -!- PATHWAY: Amino-acid biosynthesis; L-methionine biosynthesis via salvage
CC       pathway; L-methionine from S-methyl-5-thio-alpha-D-ribose 1-phosphate:
CC       step 1/6. {ECO:0000255|HAMAP-Rule:MF_01678}.
CC   -!- SIMILARITY: Belongs to the eIF-2B alpha/beta/delta subunits family.
CC       MtnA subfamily. {ECO:0000305}.
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DR   EMBL; BA000022; BAA18601.1; -; Genomic_DNA.
DR   PIR; S76472; S76472.
DR   AlphaFoldDB; P74497; -.
DR   SMR; P74497; -.
DR   IntAct; P74497; 2.
DR   STRING; 1148.1653689; -.
DR   PaxDb; P74497; -.
DR   EnsemblBacteria; BAA18601; BAA18601; BAA18601.
DR   KEGG; syn:slr1938; -.
DR   eggNOG; COG0182; Bacteria.
DR   InParanoid; P74497; -.
DR   OMA; RLWVDET; -.
DR   PhylomeDB; P74497; -.
DR   UniPathway; UPA00904; UER00874.
DR   Proteomes; UP000001425; Chromosome.
DR   GO; GO:0046523; F:S-methyl-5-thioribose-1-phosphate isomerase activity; IBA:GO_Central.
DR   GO; GO:0019509; P:L-methionine salvage from methylthioadenosine; IBA:GO_Central.
DR   GO; GO:0019284; P:L-methionine salvage from S-adenosylmethionine; IEA:UniProtKB-UniRule.
DR   Gene3D; 1.20.120.420; -; 1.
DR   Gene3D; 3.40.50.10470; -; 1.
DR   HAMAP; MF_01678; Salvage_MtnA; 1.
DR   InterPro; IPR000649; IF-2B-related.
DR   InterPro; IPR005251; IF-M1Pi.
DR   InterPro; IPR042529; IF_2B-like_C.
DR   InterPro; IPR011559; Initiation_fac_2B_a/b/d.
DR   InterPro; IPR027363; M1Pi_N.
DR   InterPro; IPR037171; NagB/RpiA_transferase-like.
DR   Pfam; PF01008; IF-2B; 1.
DR   SUPFAM; SSF100950; SSF100950; 1.
DR   TIGRFAMs; TIGR00524; eIF-2B_rel; 1.
DR   TIGRFAMs; TIGR00512; salvage_mtnA; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; Isomerase; Methionine biosynthesis;
KW   Reference proteome.
FT   CHAIN           1..351
FT                   /note="Methylthioribose-1-phosphate isomerase"
FT                   /id="PRO_0000156093"
FT   ACT_SITE        246
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         53..55
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         96
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         205
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         256..257
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   SITE            166
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
SQ   SEQUENCE   351 AA;  38282 MW;  8EF513650BE5A3C3 CRC64;
     MTQSTNFDDV YPVQWRDDQV ILIDQTRLPL EYKEVAIADY EAMGHAIKSM VVRGAPAIGV
     AAAYGMYLGA RRIQTTELRE FVVQLEFVAD QLRQTRPTAV NLFWAIDQML NVAYHSGENV
     EQIKANLLSQ AQQIQLDDLR TCQAIGAAGL EVLPREPHQL TILTHCNAGA LATAGYGTAI
     GVIRAAWSAG RLARVYADET RPRLQGAKLT VWECVQAGIP VTLITDNMAA HCMQQQRIDA
     VVVGADRIAR NGDIANKIGT YGLAVLAKMH AIPFFVAAPL STVDFALDDG SQIPIEERDP
     VEIYQPEGNR ITPEGAEFYN PAFDVTPASL ITAIITEQGA IAPEKLADLQ A