ID   MTNA_MONBE              Reviewed;         361 AA.
AC   A9UQ62;
DT   30-NOV-2010, integrated into UniProtKB/Swiss-Prot.
DT   05-FEB-2008, sequence version 1.
DT   25-MAY-2022, entry version 61.
DE   RecName: Full=Methylthioribose-1-phosphate isomerase {ECO:0000255|HAMAP-Rule:MF_03119};
DE            Short=M1Pi {ECO:0000255|HAMAP-Rule:MF_03119};
DE            Short=MTR-1-P isomerase {ECO:0000255|HAMAP-Rule:MF_03119};
DE            EC=5.3.1.23 {ECO:0000255|HAMAP-Rule:MF_03119};
DE   AltName: Full=S-methyl-5-thioribose-1-phosphate isomerase {ECO:0000255|HAMAP-Rule:MF_03119};
DE   AltName: Full=Translation initiation factor eIF-2B subunit alpha/beta/delta-like protein {ECO:0000255|HAMAP-Rule:MF_03119};
GN   ORFNames=34861;
OS   Monosiga brevicollis (Choanoflagellate).
OC   Eukaryota; Choanoflagellata; Craspedida; Salpingoecidae; Monosiga.
OX   NCBI_TaxID=81824;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=MX1 / ATCC 50154;
RX   PubMed=18273011; DOI=10.1038/nature06617;
RG   JGI Sequencing;
RA   King N., Westbrook M.J., Young S.L., Kuo A., Abedin M., Chapman J.,
RA   Fairclough S., Hellsten U., Isogai Y., Letunic I., Marr M., Pincus D.,
RA   Putnam N., Rokas A., Wright K.J., Zuzow R., Dirks W., Good M.,
RA   Goodstein D., Lemons D., Li W., Lyons J.B., Morris A., Nichols S.,
RA   Richter D.J., Salamov A., Bork P., Lim W.A., Manning G., Miller W.T.,
RA   McGinnis W., Shapiro H., Tjian R., Grigoriev I.V., Rokhsar D.;
RT   "The genome of the choanoflagellate Monosiga brevicollis and the origin of
RT   metazoans.";
RL   Nature 451:783-788(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_03119}.
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_03119};
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_03119}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_03119}.
CC       Nucleus {ECO:0000255|HAMAP-Rule:MF_03119}.
CC   -!- SIMILARITY: Belongs to the eIF-2B alpha/beta/delta subunits family.
CC       MtnA subfamily. {ECO:0000255|HAMAP-Rule:MF_03119}.
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DR   EMBL; CH991543; EDQ92992.1; -; Genomic_DNA.
DR   RefSeq; XP_001742754.1; XM_001742702.1.
DR   AlphaFoldDB; A9UQ62; -.
DR   SMR; A9UQ62; -.
DR   STRING; 81824.XP_001742754.1; -.
DR   EnsemblProtists; EDQ92992; EDQ92992; MONBRDRAFT_34861.
DR   GeneID; 5888093; -.
DR   KEGG; mbr:MONBRDRAFT_34861; -.
DR   eggNOG; KOG1468; Eukaryota.
DR   InParanoid; A9UQ62; -.
DR   OMA; RLWVDET; -.
DR   UniPathway; UPA00904; UER00874.
DR   Proteomes; UP000001357; Unassembled WGS sequence.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005634; C:nucleus; IEA:UniProtKB-SubCell.
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; Cytoplasm; Isomerase; Methionine biosynthesis;
KW   Nucleus; Reference proteome.
FT   CHAIN           1..361
FT                   /note="Methylthioribose-1-phosphate isomerase"
FT                   /id="PRO_0000402061"
FT   ACT_SITE        245
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_03119"
FT   SITE            165
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_03119"
SQ   SEQUENCE   361 AA;  38755 MW;  EBE8387C30ED8805 CRC64;
     MATLEAIKYD GEKLLVLDQI KLPLETHYDE VLSIQDGWDA IREMRVRGAP AIAIVAALTI
     AVVMKRSTFA TAAELAAFVR TSLEHLRTSR PTAVNLFEMA GRLEALLQEQ PADCTEAALR
     QAVLSYIEGM MQADIADNQA IGKFGAEAIL KDLSADVKVK VLTHCNTGSL ATARYGTALG
     VIRSLHEQQR LEHAFCTETR PYNQGARLTA YELVTEGIPG TLVADSMVSL LMKQKGISAV
     VVGADRVVAN GDTANKIGTY QIAIAAKHHG VPFFVAAPLT SVDLKLSHGS EITIEERPGK
     ELTHIFGQQL AAPGIGTWNP AFDVTPADLI TGIITERGVA YKAEGQQEFD MASFAASVGR
     A