PDBsum entry: 2j4n

Protein binding

PDB-id: 2j4n

Contents

Description

Header details

Header records

References

PROCHECK

Protein chain

100 a.a. *

* Residue conservation analysis

Tools

Clefts Calculation

PDB id:

2j4n

Name:

Protein binding

Title:

Double dockerin from piromyces equi cel45a

Structure:

Endoglucanase 45a. Chain: a. Fragment: first two dockerin domains, residues 21-118. Synonym: cel45a endoglucanase. Engineered: yes

Source:

Piromyces equi. Organism_taxid: 99929. Expressed in: escherichia coli. Expression_system_taxid: 511693.

UniProt:

Q9P868 (Q9P868_PIREQ)

Seq:

Struc:

Seq:

410 a.a.

Struc:

100 a.a.*

Key:	PfamA domain	PfamB domain
Secondary structure

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Resolution:

not givenÅ

NMR structure:

6 models

Authors:

T.Nagy,R.B.Tunnicliffe,L.D.Higgins,C.Walters,H.J.Gilbert, M.P.Williamson

Key ref:

T.Nagy et al. (2007). Characterization of a double dockerin from the cellulosome of the anaerobic fungus Piromyces equi.. J Mol Biol, 373, 612-622. [PubMed id: 17869267] [DOI: 10.1016/j.jmb.2007.08.007]

Date:

01-Sep-06

Release date:

25-Sep-07

Related entries:

1e8p characterisation of the cellulose docking domain from piromyces equi
1e8q characterisation of the cellulose docking domain from piromyces equi the type ii cohesin dockerin complex
2j4m double dockerin from piromyces equi cel45a

Quick_links

Procheck

Clefts

Surface

Key reference

DOI no: 10.1016/j.jmb.2007.08.007

J Mol Biol 373:612-622 (2007)

PubMed id: 17869267

Characterization of a double dockerin from the cellulosome of the anaerobic fungus Piromyces equi.

T.Nagy, R.B.Tunnicliffe, L.D.Higgins, C.Walters, H.J.Gilbert, M.P.Williamson.

ABSTRACT

The assembly into supramolecular complexes of proteins having complementary activities is central to cellular function. One such complex of considerable biological and industrial significance is the plant cell wall-degrading apparatus of anaerobic microorganisms, termed the cellulosome. A central feature of bacterial cellulosomes is a large non-catalytic protein, the scaffoldin, which contains multiple cohesin domains. An array of digestive enzymes is incorporated into the cellulosome through the interaction of the dockerin domains, present in the catalytic subunits, with the cohesin domains that are present in the scaffoldin. By contrast, in anaerobic fungi, such as Piromyces equi, the dockerins of cellulosomal enzymes are often present in tandem copies; however, the identity of the cognate cohesin domains in these organisms is unclear, hindering further biotechnological development of the fungal cellulosome. Here, we characterise the solution structure and function of a double-dockerin construct from the P. equi endoglucanase Cel45A. We show that the two domains are connected by a flexible linker that is short enough to keep the binding sites of the two domains on adjacent surfaces, and allows the double-dockerin construct to bind more tightly to cellulosomes than a single domain and with greater coverage. The double dockerin binds to the GH3 beta-glucosidase component of the fungal cellulosome, which is thereby identified as a potential scaffoldin.