The engL gene cluster of Clostridium cellulovorans contains a gene for cellulosomal manA.
A five-gene cluster around the gene in Clostridium cellulovorans that encodes endoglucanase EngL, which is involved in plant cell wall degradation, has been cloned and sequenced. As a result, a mannanase gene, manA, has been found downstream of engL. The manA gene consists of an open reading frame with 1,275 nucleotides encoding a protein with 425 amino acids and a molecular weight of 47, 156. ManA has a signal peptide followed by a duplicated sequence (DS, or dockerin) at its N terminus and a catalytic domain which belongs to family 5 of the glycosyl hydrolases and shows high sequence similarity with fungal mannanases, such as Agaricus bisporus Cel4 (17.3% identity), Aspergillus aculeatus Man1 (23.7% identity), and Trichoderma reesei Man1 (22.7% identity). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and N-terminal amino acid sequence analyses of the purified recombinant ManA (rManA) indicated that the N-terminal region of the rManA contained a DS and was truncated in Escherichia coli cells. Furthermore, Western blot analysis indicated that ManA is one of the cellulosomal subunits. ManA production is repressed by cellobiose.
Tamaru
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Section of Molecular and Cellular Biology, University of California, Davis, California 95616, USA.
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D002480:Cellulase / Q000235:genetics*; D003013:Clostridium / Q000235:genetics*; D008361:Mannosidases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics; D005810:Multigene Family; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D044902:beta-Mannosidase
D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D008361:Mannosidases; D044902:beta-Mannosidase; D002480:Cellulase