Three surface layer homology domains at the N terminus of the Clostridium cellulovorans major cellulosomal subunit EngE.

Abstract

The gene engE, coding for endoglucanase E, one of the three major subunits of the Clostridium cellulovorans cellulosome, has been isolated and sequenced. engE is comprised of an open reading frame (ORF) of 3,090 bp and encodes a protein of 1,030 amino acids with a molecular weight of 111,796. The amino acid sequence derived from engE revealed a structure consisting of catalytic and noncatalytic domains. The N-terminal-half region of EngE consisted of a signal peptide of 31 amino acid residues and three repeated surface layer homology (SLH) domains, which were highly conserved and homologous to an S-layer protein from the gram-negative bacterium Caulobacter crescentus. The C-terminal-half region, which is necessary for the enzymatic function of EngE and for binding of EngE to the scaffolding protein CbpA, consisted of a catalytic domain homologous to that of family 5 of the glycosyl hydrolases, a domain of unknown function, and a duplicated sequence (DS or dockerin) at its C terminus. engE is located downstream of an ORF, ORF1, that is homologous to the Bacillus subtilis phosphomethylpyrimidine kinase (pmk) gene. The unique presence of three SLH domains and a DS suggests that EngE is capable of binding both to CbpA to form a CbpA-EngE cellulosome complex and to the surface layer of C. cellulovorans.

• Authors: Y Tamaru, R H Doi
• Journal: Journal of bacteriology (J Bacteriol) Vol. 181 Issue 10 Pg. 3270-6 (May 1999) ISSN: 0021-9193 [Print] United States
• PMID: 10322032 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Protein Sorting Signals
• Recombinant Proteins
• Cellulase

Topics

• Amino Acid Sequence
• Base Sequence
• Binding Sites
• Catalytic Domain (genetics)
• Cellulase (chemistry, genetics, isolation & purification)
• Cloning, Molecular
• Clostridium (enzymology, genetics)
• Escherichia coli (genetics)
• Genes, Bacterial (genetics)
• Hydrogen-Ion Concentration
• Hydrolysis
• Models, Biological
• Molecular Sequence Data
• Molecular Weight
• Open Reading Frames (genetics)
• Protein Sorting Signals (chemistry, genetics)
• Recombinant Proteins (biosynthesis, chemistry, isolation & purification)
• Sequence Alignment
• Sequence Homology, Amino Acid
• Substrate Specificity
• Temperature