ID   NANM_ECOHS              Reviewed;         368 AA.
AC   A8A834;
DT   20-MAY-2008, integrated into UniProtKB/Swiss-Prot.
DT   23-OCT-2007, sequence version 1.
DT   25-MAY-2022, entry version 78.
DE   RecName: Full=N-acetylneuraminate epimerase {ECO:0000255|HAMAP-Rule:MF_01195};
DE            EC=5.1.3.24 {ECO:0000255|HAMAP-Rule:MF_01195};
DE   AltName: Full=N-acetylneuraminate mutarotase {ECO:0000255|HAMAP-Rule:MF_01195};
DE            Short=Neu5Ac mutarotase {ECO:0000255|HAMAP-Rule:MF_01195};
DE   AltName: Full=Sialic acid epimerase {ECO:0000255|HAMAP-Rule:MF_01195};
DE   Flags: Precursor;
GN   Name=nanM {ECO:0000255|HAMAP-Rule:MF_01195}; OrderedLocusNames=EcHS_A4535;
OS   Escherichia coli O9:H4 (strain HS).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=331112;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=HS;
RX   PubMed=18676672; DOI=10.1128/jb.00619-08;
RA   Rasko D.A., Rosovitz M.J., Myers G.S.A., Mongodin E.F., Fricke W.F.,
RA   Gajer P., Crabtree J., Sebaihia M., Thomson N.R., Chaudhuri R.,
RA   Henderson I.R., Sperandio V., Ravel J.;
RT   "The pangenome structure of Escherichia coli: comparative genomic analysis
RT   of E. coli commensal and pathogenic isolates.";
RL   J. Bacteriol. 190:6881-6893(2008).
CC   -!- FUNCTION: Converts alpha-N-acetylneuranimic acid (Neu5Ac) to the beta-
CC       anomer, accelerating the equilibrium between the alpha- and beta-
CC       anomers. Probably facilitates sialidase-negative bacteria to compete
CC       sucessfully for limited amounts of extracellular Neu5Ac, which is
CC       likely taken up in the beta-anomer. In addition, the rapid removal of
CC       sialic acid from solution might be advantageous to the bacterium to
CC       damp down host responses. {ECO:0000255|HAMAP-Rule:MF_01195}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=N-acetyl-alpha-neuraminate = N-acetyl-beta-neuraminate;
CC         Xref=Rhea:RHEA:25233, ChEBI:CHEBI:58705, ChEBI:CHEBI:58770;
CC         EC=5.1.3.24; Evidence={ECO:0000255|HAMAP-Rule:MF_01195};
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_01195}.
CC   -!- SUBCELLULAR LOCATION: Periplasm {ECO:0000255|HAMAP-Rule:MF_01195}.
CC   -!- SIMILARITY: Belongs to the NanM family. {ECO:0000255|HAMAP-
CC       Rule:MF_01195}.
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DR   EMBL; CP000802; ABV08688.1; -; Genomic_DNA.
DR   RefSeq; WP_001044128.1; NC_009800.1.
DR   AlphaFoldDB; A8A834; -.
DR   SMR; A8A834; -.
DR   KEGG; ecx:EcHS_A4535; -.
DR   HOGENOM; CLU_061535_0_0_6; -.
DR   OMA; PSTNKWR; -.
DR   Proteomes; UP000001123; Chromosome.
DR   GO; GO:0042597; C:periplasmic space; IEA:UniProtKB-SubCell.
DR   GO; GO:0016857; F:racemase and epimerase activity, acting on carbohydrates and derivatives; IEA:UniProtKB-UniRule.
DR   GO; GO:0005975; P:carbohydrate metabolic process; IEA:UniProtKB-KW.
DR   Gene3D; 2.120.10.80; -; 2.
DR   HAMAP; MF_01195; NanM; 1.
DR   InterPro; IPR015915; Kelch-typ_b-propeller.
DR   InterPro; IPR019936; Mutatrotase_YjhT-like.
DR   SUPFAM; SSF117281; SSF117281; 1.
DR   TIGRFAMs; TIGR03547; muta_rot_YjhT; 1.
PE   3: Inferred from homology;
KW   Carbohydrate metabolism; Isomerase; Kelch repeat; Periplasm; Repeat;
KW   Signal.
FT   SIGNAL          1..19
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01195"
FT   CHAIN           20..368
FT                   /note="N-acetylneuraminate epimerase"
FT                   /id="PRO_0000333060"
FT   REPEAT          40..84
FT                   /note="Kelch 1"
FT   REPEAT          86..137
FT                   /note="Kelch 2"
FT   REPEAT          139..173
FT                   /note="Kelch 3"
FT   REPEAT          174..219
FT                   /note="Kelch 4"
FT   REPEAT          222..265
FT                   /note="Kelch 5"
FT   REPEAT          287..336
FT                   /note="Kelch 6"
FT   REPEAT          338..367
FT                   /note="Kelch 7"
FT   ACT_SITE        228
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01195"
SQ   SEQUENCE   368 AA;  39557 MW;  74155BB32ABFBB43 CRC64;
     MNKTITALAI MMASFAANAS VLPETPVPFK SGTGAIDNDT VYIGLGSAGT AWYKLDTQAK
     DKKWTALAAF PGGPRDQATS AFIDGNLYVF GGIGKNSKGL TQVFNDVHKY NPKTNSWVKL
     MSHAPMGMAG HVTFVHNGKA YVTGGVNQNI FNGYFEDLNE AGKDSATIDK INAHYFDKKA
     EDYFFNKFLL SFDPSTQQWS YAGESPWYGT AGAAVVNKGD KTWLINGEAK PGLRTDAVFE
     LDFTGNNLKW NKLAPVSSPD GVAGGFAGIS NDSLIFAGGA GFKGSRENYQ NGKNYAHEGL
     KKSYSTDIHL WHNGKWDKSG ELSQGRAYGV SLPWNNSLLI IGGETAGGKA VTDSVLISVK
     DNKVTVQN