Cloning, DNA sequencing, and expression of the gene encoding Clostridium thermocellum cellulase CelJ, the largest catalytic component of the cellulosome.
AUTOR(ES)
Ahsan, M M
RESUMO
The Clostridium thermocellum F1 celJ gene, encoding endoglucanase J (CelJ), consists of an open reading frame (ORF) of 4,803 nucleotides and encodes a protein of 1,601 amino acids with a molecular weight of 178,055. The ORF was confirmed as celJ by comparison with the N-terminal sequence of a truncated CelJ derivative. CelJ is a modular enzyme composed of N-terminal signal peptide and six domains in the following order: an S-layer homology domain, a domain of unknown function (UD-1), a subfamily E1 endoglucanase domain, a family J endoglucanase domain, a docking domain, and another domain of unknown function (UD-2). UD-1 has no significant similarity to UD-2. CelJ hydrolyzed carboxymethylcellulose and xylan, and xylanase activity was ascribed to the family J domain. Antiserum raised against the truncated CelJ cross-reacted with proteins contained in the cellulosome of C. thermocellum F1. These results strongly suggest that CelJ is equivalent to S2, which was identified as the largest catalytic component in the cellulosome of C. thermocellum YS. A second but incomplete ORF encoding an enzyme classified in subfamily E2 endoglucanase, was located downstream of celJ.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=178413Documentos Relacionados
- Cloning and DNA sequence of the gene coding for Clostridium thermocellum cellulase Ss (CelS), a major cellulosome component.
- Cloning and Sequence Analysis of a New Cellulase Gene Encoding CelK, a Major Cellulosome Component of Clostridium thermocellum: Evidence for Gene Duplication and Recombination
- The anchorage function of CipA (CelL), a scaffolding protein of the Clostridium thermocellum cellulosome.
- Cloning and DNA Sequencing of the Genes Encoding Clostridium josui Scaffolding Protein CipA and Cellulase CelD and Identification of Their Gene Products as Major Components of the Cellulosome
- Nucleotide sequence of the cellulase gene celD encoding endoglucanase D of Clostridium thermocellum.
