GH7B_LIMQU
ID GH7B_LIMQU Reviewed; 448 AA.
AC D4HRL0;
DT 02-DEC-2020, integrated into UniProtKB/Swiss-Prot.
DT 18-MAY-2010, sequence version 1.
DT 03-AUG-2022, entry version 46.
DE RecName: Full=Exoglucanase GH7B {ECO:0000305};
DE EC=3.2.1.91 {ECO:0000269|PubMed:23733951};
DE AltName: Full=1,4-beta-cellobiohydrolase {ECO:0000305};
DE AltName: Full=Cellobiohydrolase 7B {ECO:0000303|PubMed:23733951};
DE Short=LqCel7B {ECO:0000303|PubMed:23733951};
DE AltName: Full=Glycosyl hydrolase family 7 protein B {ECO:0000303|PubMed:20212162};
DE Flags: Precursor;
GN Name=GH7B {ECO:0000312|EMBL:ADB85438.1};
OS Limnoria quadripunctata (Gribble).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Crustacea; Multicrustacea;
OC Malacostraca; Eumalacostraca; Peracarida; Isopoda; Limnoriidae; Limnoria.
OX NCBI_TaxID=161573;
RN [1] {ECO:0000312|EMBL:ADB85438.1}
RP NUCLEOTIDE SEQUENCE [MRNA], AND TISSUE SPECIFICITY.
RX PubMed=20212162; DOI=10.1073/pnas.0914228107;
RA King A.J., Cragg S.M., Li Y., Dymond J., Guille M.J., Bowles D.J.,
RA Bruce N.C., Graham I.A., McQueen-Mason S.J.;
RT "Molecular insight into lignocellulose digestion by a marine isopod in the
RT absence of gut microbes.";
RL Proc. Natl. Acad. Sci. U.S.A. 107:5345-5350(2010).
RN [2] {ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4HAQ}
RP X-RAY CRYSTALLOGRAPHY (1.14 ANGSTROMS) OF 19-448 IN APO FORM AND IN COMPLEX
RP WITH CELLOBIOSE, FUNCTION, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL
RP PROPERTIES, SUBUNIT, TISSUE SPECIFICITY, PYROGLUTAMATE FORMATION AT GLN-18,
RP AND DISULFIDE BONDS.
RX PubMed=23733951; DOI=10.1073/pnas.1301502110;
RA Kern M., McGeehan J.E., Streeter S.D., Martin R.N., Besser K., Elias L.,
RA Eborall W., Malyon G.P., Payne C.M., Himmel M.E., Schnorr K., Beckham G.T.,
RA Cragg S.M., Bruce N.C., McQueen-Mason S.J.;
RT "Structural characterization of a unique marine animal family 7
RT cellobiohydrolase suggests a mechanism of cellulase salt tolerance.";
RL Proc. Natl. Acad. Sci. U.S.A. 110:10189-10194(2013).
CC -!- FUNCTION: Exocellobiohydrolase (CBH) that catalyzes the hydrolysis of
CC 1,4-beta-D-glucosidic bonds in cellulose to release the disaccharide
CC cellobiose (PubMed:23733951). The degradation of cellulose involves an
CC interplay between different cellulolytic enzymes. Hydrolysis starts
CC with endoglucanases (EGs), which cut internal beta-1,4-glucosidic bonds
CC in cellulose to reduce the polymerization degree of the substrate and
CC create new chain ends for exocellobiohydrolases (CBHs). The CBHs
CC release the disaccharide cellobiose from the non-reducing end of the
CC cellulose polymer chain. Finally, beta-1,4-glucosidases hydrolyze the
CC cellobiose and other short cello-oligosaccharides into glucose units
CC (Probable). {ECO:0000269|PubMed:23733951, ECO:0000305}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=Hydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose
CC and cellotetraose, releasing cellobiose from the non-reducing ends of
CC the chains.; EC=3.2.1.91; Evidence={ECO:0000269|PubMed:23733951};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=2676.4 uM for p-nitrophenyl-beta-d-cellotrioside (pNP-G3)
CC {ECO:0000269|PubMed:23733951};
CC KM=2121.7 uM for p-nitrophenyl-beta-d-cellopentaoside (pNP-G5)
CC {ECO:0000269|PubMed:23733951};
CC Note=kcat is 10.57 min(-1) for p-nitrophenyl-beta-d-cellotrioside
CC (pNP-G3). kcat is 24.42 min(-1) for p-nitrophenyl-beta-d-
CC cellopentaoside (pNP-G5). {ECO:0000269|PubMed:23733951};
CC pH dependence:
CC Optimum pH is 4-6.5 for p-nitrophenyl-beta-d-cellotrioside (pNP-G3),
CC and 4-8 for p-nitrophenyl-beta-d-cellopentaoside (pNP-G5).
CC {ECO:0000269|PubMed:23733951};
CC Temperature dependence:
CC Optimum temperature is approximately 25-45 degrees Celsius. High
CC activity is maintained over a wide temperature range.
CC {ECO:0000269|PubMed:23733951};
CC -!- SUBUNIT: Monomer. {ECO:0000269|PubMed:23733951}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305}.
CC -!- TISSUE SPECIFICITY: Highly expressed in the hepatopancreas (at protein
CC level) (PubMed:20212162, PubMed:23733951). Little or no expression
CC detected in the hindgut or the rest of the body (at protein level)
CC (PubMed:23733951). {ECO:0000269|PubMed:20212162,
CC ECO:0000269|PubMed:23733951}.
CC -!- MISCELLANEOUS: Unlike most wood-boring animal species, which rely on
CC symbiotic microbes for digestion of woody substrates, the
CC L.quadripunctata genome contains a range of enzymes (including GH7B)
CC capable of lignocellulose digestion. {ECO:0000269|PubMed:20212162}.
CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 7 (cellulase C) family.
CC {ECO:0000305}.
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DR EMBL; FJ940757; ADB85438.1; -; mRNA.
DR PDB; 4GWA; X-ray; 1.60 A; A/B=19-448.
DR PDB; 4HAP; X-ray; 1.60 A; A/B=19-448.
DR PDB; 4HAQ; X-ray; 1.90 A; A/B=19-448.
DR PDB; 4IPM; X-ray; 1.14 A; A=19-448.
DR PDBsum; 4GWA; -.
DR PDBsum; 4HAP; -.
DR PDBsum; 4HAQ; -.
DR PDBsum; 4IPM; -.
DR AlphaFoldDB; D4HRL0; -.
DR SMR; D4HRL0; -.
DR CAZy; GH7; Glycoside Hydrolase Family 7.
DR BRENDA; 3.2.1.176; 14076.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0016162; F:cellulose 1,4-beta-cellobiosidase activity; IDA:UniProtKB.
DR GO; GO:0030245; P:cellulose catabolic process; IDA:UniProtKB.
DR CDD; cd07999; GH7_CBH_EG; 1.
DR Gene3D; 2.70.100.10; -; 1.
DR InterPro; IPR013320; ConA-like_dom_sf.
DR InterPro; IPR001722; Glyco_hydro_7.
DR InterPro; IPR037019; Glyco_hydro_7_sf.
DR PANTHER; PTHR33753; PTHR33753; 1.
DR Pfam; PF00840; Glyco_hydro_7; 1.
DR PRINTS; PR00734; GLHYDRLASE7.
DR SUPFAM; SSF49899; SSF49899; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Carbohydrate metabolism; Cellulose degradation;
KW Disulfide bond; Glycosidase; Hydrolase; Polysaccharide degradation;
KW Pyrrolidone carboxylic acid; Secreted; Signal.
FT SIGNAL 1..17
FT /evidence="ECO:0000305|PubMed:23733951"
FT CHAIN 18..448
FT /note="Exoglucanase GH7B"
FT /id="PRO_5003058923"
FT ACT_SITE 228
FT /note="Nucleophile"
FT /evidence="ECO:0000250|UniProtKB:P62694"
FT ACT_SITE 233
FT /note="Proton donor/acceptor"
FT /evidence="ECO:0000250|UniProtKB:P62694"
FT BINDING 97
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAQ"
FT BINDING 119..120
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAQ"
FT BINDING 197
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAQ"
FT BINDING 230..233
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4IPM"
FT BINDING 244
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4IPM"
FT BINDING 266
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAQ, ECO:0007744|PDB:4IPM"
FT BINDING 274
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4HAQ,
FT ECO:0007744|PDB:4IPM"
FT BINDING 396
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4IPM"
FT BINDING 412
FT /ligand="substrate"
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4HAQ,
FT ECO:0007744|PDB:4IPM"
FT MOD_RES 18
FT /note="Pyrrolidone carboxylic acid"
FT /evidence="ECO:0000269|PubMed:23733951"
FT DISULFID 62..83
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT DISULFID 73..79
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT DISULFID 154..415
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT DISULFID 188..226
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT DISULFID 192..225
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT DISULFID 246..271
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT DISULFID 254..259
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT DISULFID 276..350
FT /evidence="ECO:0000269|PubMed:23733951,
FT ECO:0007744|PDB:4GWA, ECO:0007744|PDB:4HAP,
FT ECO:0007744|PDB:4HAQ"
FT STRAND 22..24
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 29..35
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 38..46
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 48..50
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 53..55
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 61..64
FT /evidence="ECO:0007829|PDB:4IPM"
FT TURN 70..72
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 76..82
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 83..85
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 90..95
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 100..102
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 105..113
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 118..120
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 122..129
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 141..148
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 157..163
FT /evidence="ECO:0007829|PDB:4IPM"
FT TURN 167..173
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 181..183
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 197..199
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 223..225
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 228..234
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 239..244
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 246..248
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 250..254
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 256..259
FT /evidence="ECO:0007829|PDB:4IPM"
FT TURN 262..267
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 268..271
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 276..278
FT /evidence="ECO:0007829|PDB:4IPM"
FT TURN 280..284
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 287..290
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 293..296
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 301..310
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 313..323
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 326..329
FT /evidence="ECO:0007829|PDB:4IPM"
FT TURN 336..338
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 347..357
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 362..365
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 368..378
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 380..387
FT /evidence="ECO:0007829|PDB:4IPM"
FT TURN 390..394
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 395..398
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 399..402
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 413..415
FT /evidence="ECO:0007829|PDB:4IPM"
FT HELIX 422..428
FT /evidence="ECO:0007829|PDB:4IPM"
FT STRAND 433..443
FT /evidence="ECO:0007829|PDB:4IPM"
SQ SEQUENCE 448 AA; 48267 MW; E024B159B0121A0D CRC64;
MSLAVVFLLG FLAVSHGQQA GTETEEYHLP LTWERDGSSV SASVVIDSNW RWTHSTEDTT
NCYDGNEWDS TLCPDADTCT ENCAIDGVDQ GTWGDTYGIT ASGSKLTLSF VTEGEYSTDI
GSRVFLMADD DNYEIFNLLD KEFSFDVDAS NLPCGLNGAL YFVSMDEDGG TSKYSTNTAG
AKYGTGYCDA QCPHDMKFIA GKANSDGWTP SDNDQNAGTG EMGACCHEMD IWEANSQAQS
YTAHVCSVDG YTPCTGTDCG DNGDDRYKGV CDKDGCDYAA YRLGQHDFYG EGGTVDSGST
LTVITQFITG GGGLNEIRRI YQQGGQTIQN AAVNFPGDVD PYDSITEDFC VDIKRYFGDT
NDFDAKGGMS GMSNALKKGM VLVMSLWDDH YANMLWLDAT YPVDSTEPGA LRGPCSTDSG
DPADVEANFP GSTVTFSNIK IGPIQSYD
