PDBsum entry 1azh

Cellulase

PDB id: 1azh

Contents

Protein chain

36 a.a. *

* Residue conservation analysis

PDB id:

1azh

Name:

Cellulase

Title:

Three-dimensional structures of three engineered cellulose-binding domains of cellobiohydrolase i from trichoderma reesei, nmr, 14 structures

Structure:

Cellobiohydrolase i. Chain: a. Fragment: cellulose-binding domain. Synonym: cbd. Engineered: yes. Mutation: yes

Source:

Hypocrea jecorina. Organism_taxid: 51453

NMR struc:

14 models

Authors:

M.-L.Mattinen

Key ref:

M.L.Mattinen et al. (1997). Three-dimensional structures of three engineered cellulose-binding domains of cellobiohydrolase I from Trichoderma reesei. Protein Sci, 6, 294-303. PubMed id: 9041630 DOI: 10.1002/pro.5560060204

Date:

18-Nov-97 Release date: 08-Apr-98

Protein chain

P62694  (GUX1_HYPJE) -  Exoglucanase 1 from Hypocrea jecorina

Seq: 513 a.a.

Struc: 36 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.3.2.1.91 - cellulose 1,4-beta-cellobiosidase (non-reducing end).
• Reaction: Hydrolysis of 1,4-beta-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains.

DOI no: 10.1002/pro.5560060204

Protein Sci 6:294-303 (1997)

PubMed id: 9041630

Three-dimensional structures of three engineered cellulose-binding domains of cellobiohydrolase I from Trichoderma reesei.

M.L.Mattinen, M.Kontteli, J.Kerovuo, M.Linder, A.Annila, G.Lindeberg, T.Reinikainen, T.Drakenberg.

ABSTRACT

Three-dimensional solution structures for three engineered, synthetic CBDs (Y5A, Y31A, and Y32A) of cellobiohydrolase I (CBHI) from Trichoderma reesei were studied with nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopy. According to CD measurements the antiparallel beta-sheet structure of the CBD fold was preserved in all engineered peptides. The three-dimensional NMR-based structures of Y31A and Y32A revealed only small local changes due to mutations in the flat face of CBD, which is expected to bind to crystalline cellulose. Therefore, the structural roles of Y31 and Y32 are minor, but their functional importance is obvious because these mutants do not bind strongly to cellulose. In the case of Y5A, the disruption of the structural framework at the N-terminus and the complete loss of binding affinity implies that Y5 has both structural and functional significance. The number of aromatic residues and their precise spatial arrangement in the flat face of the type I CBD fold appears to be critical for specific binding. A model for the CBD binding in which the three aligned aromatic rings stack onto every other glucose ring of the cellulose polymer is discussed.