ID   MTNA_HELMI              Reviewed;         345 AA.
AC   B0TH58;
DT   16-DEC-2008, integrated into UniProtKB/Swiss-Prot.
DT   08-APR-2008, sequence version 1.
DT   03-AUG-2022, entry version 79.
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=Helmi_21080;
GN   ORFNames=HM1_2177;
OS   Heliobacterium modesticaldum (strain ATCC 51547 / Ice1).
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Heliobacteriaceae;
OC   Heliomicrobium.
OX   NCBI_TaxID=498761;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 51547 / Ice1;
RX   PubMed=18441057; DOI=10.1128/jb.00299-08;
RA   Sattley W.M., Madigan M.T., Swingley W.D., Cheung P.C., Clocksin K.M.,
RA   Conrad A.L., Dejesa L.C., Honchak B.M., Jung D.O., Karbach L.E.,
RA   Kurdoglu A., Lahiri S., Mastrian S.D., Page L.E., Taylor H.L., Wang Z.T.,
RA   Raymond J., Chen M., Blankenship R.E., Touchman J.W.;
RT   "The genome of Heliobacterium modesticaldum, a phototrophic representative
RT   of the Firmicutes containing the simplest photosynthetic apparatus.";
RL   J. Bacteriol. 190:4687-4696(2008).
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; CP000930; ABZ84733.1; -; Genomic_DNA.
DR   RefSeq; WP_012283233.1; NC_010337.2.
DR   AlphaFoldDB; B0TH58; -.
DR   SMR; B0TH58; -.
DR   STRING; 498761.HM1_2177; -.
DR   EnsemblBacteria; ABZ84733; ABZ84733; HM1_2177.
DR   KEGG; hmo:HM1_2177; -.
DR   eggNOG; COG0182; Bacteria.
DR   HOGENOM; CLU_016218_1_2_9; -.
DR   OMA; RLWVDET; -.
DR   OrthoDB; 1290468at2; -.
DR   UniPathway; UPA00904; UER00874.
DR   Proteomes; UP000008550; Chromosome.
DR   GO; GO:0046523; F:S-methyl-5-thioribose-1-phosphate isomerase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0019509; P:L-methionine salvage from methylthioadenosine; IEA:UniProtKB-UniPathway.
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..345
FT                   /note="Methylthioribose-1-phosphate isomerase"
FT                   /id="PRO_0000357195"
FT   ACT_SITE        235
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         44..46
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         87
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         194
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         245..246
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   SITE            155
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
SQ   SEQUENCE   345 AA;  37558 MW;  D118B85AFBEF845C CRC64;
     MDTMRWQDDH LLLLDQTKLP LTEEYIECWD HVILCDAIKK LKVRGAPAIG AAAAFGVALA
     ALNYTGEDRA EFEADVKKAI ADLGKTRPTA VNLFWALRRM EAVLEDIRTY SVKEQQERLI
     AEAKAVFDED RAMNEQMGQY GLELIPESAG ILTHCNAGAL ATAGFGTALG VIRAAHRAGK
     EISVFADETR PLLQGARLTA WELMQDGIPV TLITDSMAAY VMKQKLVDLV IVGADRITAN
     GDVANKIGTY GVALAAKAHG IPFYVAAPVS TFDLSLESGL QIPIEERDTE EVRRVGDSIT
     APPGVPVYNP AFDVTPAELV TAFITDRGVF RPPYLETLRA MAETK