| IED ID | IndEnz0008000203 |
| Enzyme Type ID | cellulase000203 |
| Protein Name |
Exoglucanase GH7B EC 3.2.1.91 1,4-beta-cellobiohydrolase Cellobiohydrolase 7B LqCel7B Glycosyl hydrolase family 7 protein B |
| Gene Name | GH7B |
| Organism | Limnoria quadripunctata (Gribble) |
| Taxonomic Lineage | cellular organisms Eukaryota Opisthokonta Metazoa Eumetazoa Bilateria Protostomia Ecdysozoa Panarthropoda Arthropoda Mandibulata Pancrustacea Crustacea Multicrustacea Malacostraca Eumalacostraca Peracarida Isopoda (pill bugs wood lice and sea slaters) Flabellifera Limnoriidae Limnoria Limnoria quadripunctata (Gribble) |
| Enzyme Sequence | MSLAVVFLLGFLAVSHGQQAGTETEEYHLPLTWERDGSSVSASVVIDSNWRWTHSTEDTTNCYDGNEWDSTLCPDADTCTENCAIDGVDQGTWGDTYGITASGSKLTLSFVTEGEYSTDIGSRVFLMADDDNYEIFNLLDKEFSFDVDASNLPCGLNGALYFVSMDEDGGTSKYSTNTAGAKYGTGYCDAQCPHDMKFIAGKANSDGWTPSDNDQNAGTGEMGACCHEMDIWEANSQAQSYTAHVCSVDGYTPCTGTDCGDNGDDRYKGVCDKDGCDYAAYRLGQHDFYGEGGTVDSGSTLTVITQFITGGGGLNEIRRIYQQGGQTIQNAAVNFPGDVDPYDSITEDFCVDIKRYFGDTNDFDAKGGMSGMSNALKKGMVLVMSLWDDHYANMLWLDATYPVDSTEPGALRGPCSTDSGDPADVEANFPGSTVTFSNIKIGPIQSYD |
| Enzyme Length | 448 |
| Uniprot Accession Number | D4HRL0 |
| Absorption | |
| Active Site | ACT_SITE 228; /note=Nucleophile; /evidence=ECO:0000250|UniProtKB:P62694; ACT_SITE 233; /note=Proton donor/acceptor; /evidence=ECO:0000250|UniProtKB:P62694 |
| Activity Regulation | |
| Binding Site | BINDING 97; /note="Substrate"; /evidence="ECO:0000269|PubMed:23733951, ECO:0007744|PDB:4HAQ"; BINDING 197; /note="Substrate"; /evidence="ECO:0000269|PubMed:23733951, ECO:0007744|PDB:4HAQ"; BINDING 244; /note="Substrate"; /evidence="ECO:0000269|PubMed:23733951, ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4IPM"; BINDING 266; /note="Substrate"; /evidence="ECO:0000269|PubMed:23733951, ECO:0007744|PDB:4HAQ, ECO:0007744|PDB:4IPM"; BINDING 274; /note="Substrate; via carbonyl oxygen"; /evidence="ECO:0000269|PubMed:23733951, ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4HAQ, ECO:0007744|PDB:4IPM"; BINDING 396; /note="Substrate"; /evidence="ECO:0000269|PubMed:23733951, ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4IPM"; BINDING 412; /note="Substrate"; /evidence="ECO:0000269|PubMed:23733951, ECO:0007744|PDB:4HAP, ECO:0007744|PDB:4HAQ, ECO:0007744|PDB:4IPM" |
| Calcium Binding | |
| catalytic Activity | CATALYTIC ACTIVITY: Reaction=Hydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains.; EC=3.2.1.91; Evidence={ECO:0000269|PubMed:23733951}; |
| DNA Binding | |
| EC Number | 3.2.1.91 |
| Enzyme Function | FUNCTION: Exocellobiohydrolase (CBH) that catalyzes the hydrolysis of 1,4-beta-D-glucosidic bonds in cellulose to release the disaccharide cellobiose (PubMed:23733951). The degradation of cellulose involves an interplay between different cellulolytic enzymes. Hydrolysis starts with endoglucanases (EGs), which cut internal beta-1,4-glucosidic bonds in cellulose to reduce the polymerization degree of the substrate and create new chain ends for exocellobiohydrolases (CBHs). The CBHs release the disaccharide cellobiose from the non-reducing end of the cellulose polymer chain. Finally, beta-1,4-glucosidases hydrolyze the cellobiose and other short cello-oligosaccharides into glucose units (Probable). {ECO:0000269|PubMed:23733951, ECO:0000305}. |
| Temperature Dependency | BIOPHYSICOCHEMICAL PROPERTIES: Temperature dependence: Optimum temperature is approximately 25-45 degrees Celsius. High activity is maintained over a wide temperature range. {ECO:0000269|PubMed:23733951}; |
| PH Dependency | BIOPHYSICOCHEMICAL PROPERTIES: pH dependence: Optimum pH is 4-6.5 for p-nitrophenyl-beta-d-cellotrioside (pNP-G3), and 4-8 for p-nitrophenyl-beta-d-cellopentaoside (pNP-G5). {ECO:0000269|PubMed:23733951}; |
| Pathway | |
| nucleotide Binding | |
| Features | Active site (2); Beta strand (29); Binding site (7); Chain (1); Disulfide bond (8); Helix (10); Modified residue (1); Region (2); Signal peptide (1); Turn (6) |
| Keywords | 3D-structure;Carbohydrate metabolism;Cellulose degradation;Disulfide bond;Glycosidase;Hydrolase;Polysaccharide degradation;Pyrrolidone carboxylic acid;Secreted;Signal |
| Interact With | |
| Induction | |
| Subcellular Location | SUBCELLULAR LOCATION: Secreted {ECO:0000305}. |
| Modified Residue | MOD_RES 18; /note=Pyrrolidone carboxylic acid; /evidence=ECO:0000269|PubMed:23733951 |
| Post Translational Modification | |
| Signal Peptide | SIGNAL 1..17; /evidence=ECO:0000305|PubMed:23733951 |
| Structure 3D | X-ray crystallography (4) |
| Cross Reference PDB | 4GWA; 4HAP; 4HAQ; 4IPM; |
| Mapped Pubmed ID | - |
| Motif | |
| Gene Encoded By | |
| Mass | 48,267 |
| Kinetics | BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=2676.4 uM for p-nitrophenyl-beta-d-cellotrioside (pNP-G3) {ECO:0000269|PubMed:23733951}; KM=2121.7 uM for p-nitrophenyl-beta-d-cellopentaoside (pNP-G5) {ECO:0000269|PubMed:23733951}; Note=kcat is 10.57 min(-1) for p-nitrophenyl-beta-d-cellotrioside (pNP-G3). kcat is 24.42 min(-1) for p-nitrophenyl-beta-d-cellopentaoside (pNP-G5). {ECO:0000269|PubMed:23733951}; |
| Metal Binding | |
| Rhea ID | |
| Cross Reference Brenda | 3.2.1.176; |