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Protein

Exoglucanase 2

Gene

cbh2

Organism
Hypocrea jecorina (Trichoderma reesei)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Exocellobiohydrolases (CBH) that catalyzes the hydrolysis of 1,4-beta-D-glucosidic bonds in cellulose to release the disaccharide cellobiose (Ref. 3). The degradation of cellulose involves an interplay between different cellulolytic enzymes. Hydolysis 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).Curated1 Publication

Miscellaneous

T.reesei produces two different exocellobiohydrolases. They are unique in that they can hydrolyze crystalline cellulose in the absence of endoglucanases.

Catalytic activityi

Hydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains.1 Publication

Kineticsi

kcat is 0.06 sec(-1) with cellotriose as substrate, 4.1 sec(-1) with cellotetraose as substrate, 1.1 sec(-1) with cellopentaose as substrate and 14 sec(-1) with cellopentaose as substrate.1 Publication
  1. KM=17 µM for cellotriose1 Publication
  2. KM=2.6 µM for cellotetraose1 Publication
  3. KM=1.3 µM for cellopentaose1 Publication
  4. KM=14 µM for cellohexaose1 Publication

    pH dependencei

    Optimum pH is 4-6.1 Publication

    Sites

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Sitei199Transition state stabilizer that also modulates the pKa of Asp-245 and may act as a proton acceptor through a water chain1 Publication1
    Active sitei245Proton donor1 Publication1

    GO - Molecular functioni

    • cellulose 1,4-beta-cellobiosidase activity Source: UniProtKB-EC
    • cellulose binding Source: InterPro
    • identical protein binding Source: IntAct

    GO - Biological processi

    Keywordsi

    Molecular functionGlycosidase, Hydrolase
    Biological processCarbohydrate metabolism, Cellulose degradation, Polysaccharide degradation

    Enzyme and pathway databases

    BRENDAi3.2.1.91. 6451.

    Protein family/group databases

    CAZyiCBM1. Carbohydrate-Binding Module Family 1.
    GH6. Glycoside Hydrolase Family 6.
    mycoCLAPiCBH6B_TRIRE.

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Exoglucanase 2 (EC:3.2.1.91)
    Alternative name(s):
    1,4-beta-cellobiohydrolase
    Cellobiohydrolase 6A
    Short name:
    Cel6A
    Exocellobiohydrolase II
    Short name:
    CBHII
    Exoglucanase II
    Gene namesi
    Name:cbh2
    OrganismiHypocrea jecorina (Trichoderma reesei)
    Taxonomic identifieri51453 [NCBI]
    Taxonomic lineageiEukaryotaFungiDikaryaAscomycotaPezizomycotinaSordariomycetesHypocreomycetidaeHypocrealesHypocreaceaeTrichoderma

    Subcellular locationi

    Extracellular region or secreted Cytosol Plasma membrane Cell wall Cytoskeleton Vacuole Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

    Keywords - Cellular componenti

    Secreted

    Pathology & Biotechi

    Mutagenesis

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Mutagenesisi199D → A: 20% of wild-type activity. 1 Publication1
    Mutagenesisi245D → A: No measurable activity. 1 Publication1

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Signal peptidei1 – 18Sequence analysisAdd BLAST18
    PropeptideiPRO_000044127719 – 241 Publication6
    ChainiPRO_000000791125 – 471Exoglucanase 2Add BLAST447

    Amino acid modifications

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Modified residuei25Pyrrolidone carboxylic acid1 Publication1
    Glycosylationi111O-linked (Man...) threonine2 Publications1
    Glycosylationi121O-linked (Man...) threonine2 Publications1
    Glycosylationi130O-linked (Man...) serine2 Publications1
    Glycosylationi133O-linked (Man...) serine2 Publications1
    Glycosylationi134O-linked (Man...) serine2 Publications1
    Glycosylationi139O-linked (Man...) serine2 Publications1
    Glycosylationi146O-linked (Man...) threonine2 Publications1
    Disulfide bondi200 ↔ 2592 Publications
    Glycosylationi313N-linked (GlcNAc) asparagine2 Publications1
    Glycosylationi334N-linked (GlcNAc...) (high mannose) asparagine2 Publications1
    Disulfide bondi392 ↔ 4392 Publications

    Post-translational modificationi

    Asn-334 contains mainly a high-mannose-type glycan (Hex7-9GlcNAc2) in a 3:1 ration with a single GlcNAc. Asn-313 was primarily unglycosylated with a small fraction (18%) bearing a single GlcNAc at this site.By similarity

    Sites

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Sitei38Not glycosylatedBy similarity1

    Keywords - PTMi

    Disulfide bond, Glycoprotein, Pyrrolidone carboxylic acid

    PTM databases

    iPTMnetiP07987.

    Interactioni

    Binary interactionsi

    WithEntry#Exp.IntActNotes
    itself2EBI-8155616,EBI-8155616

    GO - Molecular functioni

    • identical protein binding Source: IntAct

    Protein-protein interaction databases

    MINTiMINT-8401560.

    Structurei

    Secondary structure

    1471
    Legend: HelixTurnBeta strandPDB Structure known for this area
    Show more details
    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Turni116 – 119Combined sources4
    Beta strandi120 – 122Combined sources3
    Helixi126 – 135Combined sources10
    Helixi137 – 139Combined sources3
    Helixi142 – 151Combined sources10
    Beta strandi158 – 160Combined sources3
    Helixi163 – 165Combined sources3
    Helixi166 – 181Combined sources16
    Beta strandi186 – 192Combined sources7
    Beta strandi202 – 204Combined sources3
    Helixi211 – 213Combined sources3
    Helixi215 – 232Combined sources18
    Turni233 – 235Combined sources3
    Beta strandi238 – 242Combined sources5
    Beta strandi244 – 246Combined sources3
    Helixi247 – 252Combined sources6
    Helixi257 – 276Combined sources20
    Beta strandi282 – 287Combined sources6
    Helixi291 – 294Combined sources4
    Helixi297 – 313Combined sources17
    Beta strandi320 – 326Combined sources7
    Helixi340 – 342Combined sources3
    Helixi350 – 363Combined sources14
    Beta strandi370 – 374Combined sources5
    Beta strandi379 – 382Combined sources4
    Beta strandi392 – 396Combined sources5
    Beta strandi403 – 405Combined sources3
    Beta strandi410 – 416Combined sources7
    Beta strandi432 – 434Combined sources3
    Helixi437 – 440Combined sources4
    Helixi456 – 464Combined sources9

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    PDB entryMethodResolution (Å)ChainPositionsPDBsum
    1CB2X-ray2.00A/B107-471[»]
    1HGWX-ray2.10A/B107-471[»]
    1HGYX-ray2.20A/B107-471[»]
    1QJWX-ray1.90A/B107-471[»]
    1QK0X-ray2.10A/B109-471[»]
    1QK2X-ray2.00A/B109-471[»]
    3CBHX-ray2.00A107-471[»]
    4AU0X-ray1.70A/B109-471[»]
    4AX6X-ray2.30A/B109-471[»]
    4AX7X-ray1.70A/B/C/D109-471[»]
    4I5RX-ray1.50A158-331[»]
    A425-471[»]
    4I5UX-ray1.22A158-331[»]
    A425-471[»]
    ProteinModelPortaliP07987.
    SMRiP07987.
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiP07987.

    Family & Domainsi

    Domains and Repeats

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Domaini26 – 62CBM1PROSITE-ProRule annotationAdd BLAST37

    Region

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Regioni66 – 106LinkerCuratedAdd BLAST41
    Regioni107 – 471Catalytic1 PublicationAdd BLAST365

    Domaini

    The enzyme consists of two functional domains, a catalytic core joined to a carbohydrate-binding domain (CBM) by a serine-, threonine-, and proline-rich, highly glycosylated linker sequence.Curated

    Sequence similaritiesi

    Keywords - Domaini

    Signal

    Phylogenomic databases

    eggNOGiENOG410IEPE. Eukaryota.
    COG5297. LUCA.
    OMAiKCANAQS.

    Family and domain databases

    Gene3Di3.20.20.40. 1 hit.
    InterProiView protein in InterPro
    IPR016288. Beta_cellobiohydrolase.
    IPR036434. Beta_cellobiohydrolase_sf.
    IPR035971. CBD_sf.
    IPR000254. Cellulose-bd_dom_fun.
    IPR001524. Glyco_hydro_6_CS.
    PANTHERiPTHR34876. PTHR34876. 1 hit.
    PfamiView protein in Pfam
    PF00734. CBM_1. 1 hit.
    PF01341. Glyco_hydro_6. 1 hit.
    PIRSFiPIRSF001100. Beta_cellobiohydrolase. 1 hit.
    PRINTSiPR00733. GLHYDRLASE6.
    ProDomiView protein in ProDom or Entries sharing at least one domain
    PD001821. CBD_fun. 1 hit.
    SMARTiView protein in SMART
    SM00236. fCBD. 1 hit.
    SUPFAMiSSF51989. SSF51989. 1 hit.
    SSF57180. SSF57180. 1 hit.
    PROSITEiView protein in PROSITE
    PS00562. CBM1_1. 1 hit.
    PS51164. CBM1_2. 1 hit.
    PS00655. GLYCOSYL_HYDROL_F6_1. 1 hit.
    PS00656. GLYCOSYL_HYDROL_F6_2. 1 hit.

    Sequencei

    Sequence statusi: Complete.

    Sequence processingi: The displayed sequence is further processed into a mature form.

    P07987-1 [UniParc]FASTAAdd to basket

    « Hide

            10         20         30         40         50
    MIVGILTTLA TLATLAASVP LEERQACSSV WGQCGGQNWS GPTCCASGST
    60 70 80 90 100
    CVYSNDYYSQ CLPGAASSSS STRAASTTSR VSPTTSRSSS ATPPPGSTTT
    110 120 130 140 150
    RVPPVGSGTA TYSGNPFVGV TPWANAYYAS EVSSLAIPSL TGAMATAAAA
    160 170 180 190 200
    VAKVPSFMWL DTLDKTPLME QTLADIRTAN KNGGNYAGQF VVYDLPDRDC
    210 220 230 240 250
    AALASNGEYS IADGGVAKYK NYIDTIRQIV VEYSDIRTLL VIEPDSLANL
    260 270 280 290 300
    VTNLGTPKCA NAQSAYLECI NYAVTQLNLP NVAMYLDAGH AGWLGWPANQ
    310 320 330 340 350
    DPAAQLFANV YKNASSPRAL RGLATNVANY NGWNITSPPS YTQGNAVYNE
    360 370 380 390 400
    KLYIHAIGPL LANHGWSNAF FITDQGRSGK QPTGQQQWGD WCNVIGTGFG
    410 420 430 440 450
    IRPSANTGDS LLDSFVWVKP GGECDGTSDS SAPRFDSHCA LPDALQPAPQ
    460 470
    AGAWFQAYFV QLLTNANPSF L
    Length:471
    Mass (Da):49,653
    Last modified:August 1, 1988 - v1
    Checksum:iC4711BC335B1BD88
    GO

    Experimental Info

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Sequence conflicti359P → R in AAA72922 (Ref. 2) Curated1
    Sequence conflicti449P → A in AAA72922 (Ref. 2) Curated1

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    M16190 Genomic DNA. Translation: AAA34210.1.
    M55080 Genomic DNA. Translation: AAA72922.1.
    PIRiA26160.

    Similar proteinsi

    Entry informationi

    Entry nameiGUX2_HYPJE
    AccessioniPrimary (citable) accession number: P07987
    Entry historyiIntegrated into UniProtKB/Swiss-Prot: August 1, 1988
    Last sequence update: August 1, 1988
    Last modified: November 22, 2017
    This is version 147 of the entry and version 1 of the sequence. See complete history.
    Entry statusiReviewed (UniProtKB/Swiss-Prot)
    Annotation programFungal Protein Annotation Program

    Miscellaneousi

    Keywords - Technical termi

    3D-structure, Direct protein sequencing

    Documents

    1. Glycosyl hydrolases
      Classification of glycosyl hydrolase families and list of entries
    2. PDB cross-references
      Index of Protein Data Bank (PDB) cross-references
    3. SIMILARITY comments
      Index of protein domains and families