ID   MTNA_CROS5              Reviewed;         345 AA.
AC   B1WQH2;
DT   16-DEC-2008, integrated into UniProtKB/Swiss-Prot.
DT   16-DEC-2008, sequence version 2.
DT   03-AUG-2022, entry version 65.
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=cce_2333;
OS   Crocosphaera subtropica (strain ATCC 51142 / BH68) (Cyanothece sp. (strain
OS   ATCC 51142)).
OC   Bacteria; Cyanobacteria; Oscillatoriophycideae; Chroococcales;
OC   Aphanothecaceae; Crocosphaera; Crocosphaera subtropica.
OX   NCBI_TaxID=43989;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 51142 / BH68;
RX   PubMed=18812508; DOI=10.1073/pnas.0805418105;
RA   Welsh E.A., Liberton M., Stoeckel J., Loh T., Elvitigala T., Wang C.,
RA   Wollam A., Fulton R.S., Clifton S.W., Jacobs J.M., Aurora R., Ghosh B.K.,
RA   Sherman L.A., Smith R.D., Wilson R.K., Pakrasi H.B.;
RT   "The genome of Cyanothece 51142, a unicellular diazotrophic cyanobacterium
RT   important in the marine nitrogen cycle.";
RL   Proc. Natl. Acad. Sci. U.S.A. 105:15094-15099(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}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=ACB51683.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; CP000806; ACB51683.1; ALT_INIT; Genomic_DNA.
DR   RefSeq; WP_035857660.1; NC_010546.1.
DR   AlphaFoldDB; B1WQH2; -.
DR   SMR; B1WQH2; -.
DR   STRING; 43989.cce_2333; -.
DR   EnsemblBacteria; ACB51683; ACB51683; cce_2333.
DR   KEGG; cyt:cce_2333; -.
DR   eggNOG; COG0182; Bacteria.
DR   HOGENOM; CLU_016218_1_2_3; -.
DR   OrthoDB; 1290468at2; -.
DR   UniPathway; UPA00904; UER00874.
DR   Proteomes; UP000001203; Chromosome circular.
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_0000357169"
FT   ACT_SITE        240
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         47..49
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         90
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         199
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   BINDING         250..251
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
FT   SITE            160
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01678"
SQ   SEQUENCE   345 AA;  37939 MW;  43F6E2692F41B200 CRC64;
     MNTIYPVIWS NNKVLLIDQT SLPSRYTLVE ISRYEDMAKA IKTMIVRGAP AIGVAAAYGM
     YLGARDIQTQ DRETFLKHLD KIAQILRQTR PTAVNLFWAI SRMLKTAYET LGTVEEIKKI
     LLETAQKIQE EDLQTCQAIG HNSLSILPTN PEKLTILTHC NAGALATAGY GTALGVIRSV
     WTAGRLNRVF ADETRPRLQG AKLTAWECVQ EKIPVTVISD NMAAHCMQKG LIDMVVVGAD
     RIAANGDTAN KIGTYGLAVI AKMHQVPFYV AAPLSTVDFS LETGDLIPIE ERDPSELYQI
     GNTVIYPDGV DYYNPAFDVT PADLITGIIT EQKTVNPKEL ITLKG