HEX1_VIBFU
ID HEX1_VIBFU Reviewed; 611 AA.
AC P96155;
DT 15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-1997, sequence version 1.
DT 03-AUG-2022, entry version 105.
DE RecName: Full=Beta-hexosaminidase {ECO:0000305};
DE EC=3.2.1.52 {ECO:0000269|PubMed:8969205};
DE AltName: Full=Beta-N-acetylhexosaminidase {ECO:0000305};
DE AltName: Full=N-acetyl-beta-glucosaminidase {ECO:0000305};
GN Name=exoI {ECO:0000303|PubMed:8969205};
OS Vibrio furnissii.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Vibrionales; Vibrionaceae;
OC Vibrio.
OX NCBI_TaxID=29494;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-20, FUNCTION,
RP CATALYTIC ACTIVITY, ACTIVITY REGULATION, BIOPHYSICOCHEMICAL PROPERTIES,
RP PATHWAY, SUBUNIT, SUBCELLULAR LOCATION, AND INDUCTION.
RX PubMed=8969205; DOI=10.1074/jbc.271.52.33425;
RA Keyhani N.O., Roseman S.;
RT "The chitin catabolic cascade in the marine bacterium Vibrio furnissii.
RT Molecular cloning, isolation, and characterization of a periplasmic beta-N-
RT acetylglucosaminidase.";
RL J. Biol. Chem. 271:33425-33432(1996).
CC -!- FUNCTION: Hydrolyzes aryl-N-acetyl-beta-D-glucosaminide (aryl-beta-
CC GlcNAc), aryl-beta-GalNAc and chitin oligosaccharides. Can hydrolyze
CC rapidly the artificial substrates p-nitrophenyl-N-acetyl-beta-D-
CC glucosaminide (PNP-beta-GlcNAc) and 4-methylumbelliferyl-beta-GlcNAc,
CC and is slightly active on p-nitrophenyl-beta-GalNAc. This enzyme is not
CC processive, i.e. when it hydrolyzes (GlcNAc)n, both products, (Glc-
CC NAc)n-1 and the terminal GlcNAc, are released before the enzyme attacks
CC a second molecule of (GlcNAc)n or (GlcNAc)n-1.
CC {ECO:0000269|PubMed:8969205}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine
CC residues in N-acetyl-beta-D-hexosaminides.; EC=3.2.1.52;
CC Evidence={ECO:0000269|PubMed:8969205};
CC -!- ACTIVITY REGULATION: Inhibited by mercuric ions, PNP-beta-Glc, PNP-
CC beta-Gal, PNP-alpha-GlcNAc, and PNP-beta-S-GlcNAc.
CC {ECO:0000269|PubMed:8969205}.
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=1.7 mM for (GlcNAc)2 {ECO:0000269|PubMed:8969205};
CC KM=0.83 mM for (GlcNAc)3 {ECO:0000269|PubMed:8969205};
CC KM=0.78 mM for (GlcNAc)4 {ECO:0000269|PubMed:8969205};
CC KM=3.7 mM for (GlcNAc)5 {ECO:0000269|PubMed:8969205};
CC KM=3.5 mM for (GlcNAc)6 {ECO:0000269|PubMed:8969205};
CC KM=0.09 mM for PNP-GlcNAc {ECO:0000269|PubMed:8969205};
CC KM=0.33 mM for PNP-GalNAc {ECO:0000269|PubMed:8969205};
CC Vmax=53.6 umol/min/mg enzyme with (GlcNAc)2 as substrate
CC {ECO:0000269|PubMed:8969205};
CC Vmax=335 umol/min/mg enzyme with (GlcNAc)3 as substrate
CC {ECO:0000269|PubMed:8969205};
CC Vmax=376 umol/min/mg enzyme with (GlcNAc)4 as substrate
CC {ECO:0000269|PubMed:8969205};
CC Vmax=365 umol/min/mg enzyme with (GlcNAc)5 as substrate
CC {ECO:0000269|PubMed:8969205};
CC Vmax=376 umol/min/mg enzyme with (GlcNAc)6 as substrate
CC {ECO:0000269|PubMed:8969205};
CC Vmax=270 umol/min/mg enzyme with PNP-GlcNAc as substrate
CC {ECO:0000269|PubMed:8969205};
CC Vmax=130 umol/min/mg enzyme with PNP-GalNAc as substrate
CC {ECO:0000269|PubMed:8969205};
CC pH dependence:
CC Optimum pH is 7.0 with (Glc-NAc)n (n=3-6) as substrate and 5.8 with
CC (GlcNAc)2 as substrate. {ECO:0000269|PubMed:8969205};
CC Temperature dependence:
CC Optimum temperature is 35-40 degrees Celsius.
CC {ECO:0000269|PubMed:8969205};
CC -!- PATHWAY: Glycan degradation; chitin degradation.
CC {ECO:0000269|PubMed:8969205}.
CC -!- SUBUNIT: Homodimer. {ECO:0000305|PubMed:8969205}.
CC -!- SUBCELLULAR LOCATION: Periplasm {ECO:0000269|PubMed:8969205}.
CC -!- INDUCTION: By (GlcNAc)2. {ECO:0000269|PubMed:8969205}.
CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 20 family. {ECO:0000305}.
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DR EMBL; U41417; AAC44672.1; -; Genomic_DNA.
DR AlphaFoldDB; P96155; -.
DR SMR; P96155; -.
DR CAZy; GH20; Glycoside Hydrolase Family 20.
DR BioCyc; MetaCyc:MONMETA-16856; -.
DR BRENDA; 3.2.1.52; 6631.
DR UniPathway; UPA00349; -.
DR GO; GO:0042597; C:periplasmic space; IEA:UniProtKB-SubCell.
DR GO; GO:0004563; F:beta-N-acetylhexosaminidase activity; IEA:UniProtKB-EC.
DR GO; GO:0102148; F:N-acetyl-beta-D-galactosaminidase activity; IEA:UniProtKB-EC.
DR GO; GO:0006032; P:chitin catabolic process; IEA:UniProtKB-UniPathway.
DR GO; GO:0000272; P:polysaccharide catabolic process; IEA:UniProtKB-KW.
DR Gene3D; 3.30.379.10; -; 1.
DR InterPro; IPR025705; Beta_hexosaminidase_sua/sub.
DR InterPro; IPR015883; Glyco_hydro_20_cat.
DR InterPro; IPR017853; Glycoside_hydrolase_SF.
DR InterPro; IPR029018; Hex-like_dom2.
DR InterPro; IPR015882; HEX_bac_N.
DR PANTHER; PTHR22600; PTHR22600; 1.
DR Pfam; PF00728; Glyco_hydro_20; 1.
DR Pfam; PF02838; Glyco_hydro_20b; 1.
DR PRINTS; PR00738; GLHYDRLASE20.
DR SUPFAM; SSF51445; SSF51445; 1.
DR SUPFAM; SSF55545; SSF55545; 1.
PE 1: Evidence at protein level;
KW Carbohydrate metabolism; Chitin degradation; Direct protein sequencing;
KW Glycosidase; Hydrolase; Periplasm; Polysaccharide degradation.
FT CHAIN 1..611
FT /note="Beta-hexosaminidase"
FT /id="PRO_0000215377"
SQ SEQUENCE 611 AA; 69502 MW; E04C700E88F4D8C3 CRC64;
MNYRIDFAVL SEHPQFCRFG LTLHNLSDQD LKAWSLHFTI DRYIQPDSIS HSQIHQVGSF
CSLTPEQDVI NSNSHFYCEF SIKTAPFPFH YYTDGIKAAF VQINDVEPRV RHDVIVTPIA
LASPYRERSE IPATDAATLS LLPKPNHIER LDGEFALTAG SQISLQSSCA ETAATWLKQE
LTHLYQWQPH DIGSADIVLR TNPTLDEGAY LLSVDRKPIR LEASSHIGFV HASATLLQLV
RPDGDNLLVP HIVIKDAPRF KYRGMMLDCA RHFHPLERVK RLINQLAHYK FNTFHWHLTD
DEGWRIEIKS LPQLTDIGAW RGVDEVLEPQ YSLLTEKHGG FYTQEEIREV IAYAAERGIT
VIPEIDIPGH SRAAIKALPE WLFDEDDQSQ YRSIQYYNDN VLSPALPGTY RFLDCVLEEV
AALFPSHFIH IGADEVPDGV WVNSPKCQAL MAEEGYTDAK ELQGHLLRYA EKKLKSLGKR
MVGWEEAQHG DKVSKDTVIY SWLSEQAALN CARQGFDVIL QPGQFTYLDI AQDYAPEEPG
VDWAGVTPLE RAYRYEPLVE VPEHDPLRKR ILGIQCALWC ELVNNQDRMD YMIYPRLTAL
AGSGLDTKIP A
