HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 277, Issue 33, 29555-29560, August 16, 2002

This Article Full Text Full Text (PDF) All Versions of this Article: 277/33/29555    most recent M202978200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Park, J. K. Articles by Roseman, S. Search for Related Content PubMed PubMed Citation Articles by Park, J. K. Articles by Roseman, S. Social Bookmarking                      What's this?

Molecular Cloning and Characterization of a Unique -Glucosidase from Vibrio cholerae^*

Jae Kweon Park^§, Lai-Xi Wang^¶, Himatkumar V. Patel, and Saul Roseman

From the  Department of Biology and the McCollum-Pratt Institute, The Johns Hopkins University, Baltimore, Maryland 21218 and ^¶ Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland 21201

We have recently reported the molecular cloning of a gene, gspK, in Vibrio cholerae that encodes a specific glucosamine kinase. We describe here the identification of bglA, a gene contiguous to gspK in a presumptive large chitin catabolic operon. BglA was molecularly cloned into Escherichia coli, and the protein BglA was overexpressed and purified to apparent homogeneity. BglA is 65 kDa (574 amino acids) with an N-terminal amino acid sequence predicted by the gene sequence, suggesting that the enzyme is cytoplasmic. The purified enzyme exhibited optimal activity with p-nitrophenyl -glucoside, cellobiose, and higher oligosaccharides of cellulose. No other glucosides or glycosides tested were hydrolyzed, including Glc-Glc disaccharides where the linkage is 12, 13, and 16, respectively. The predicted BglA sequence bears little similarity to other proteins in the data banks. The Henrissat algorithm places BglA sequence in Family 9 of the glycosidases, suggesting it is an endoglucanase. However, the results summarized above suggested that BglA is an exoenzyme yielding Glc at each cleavage step. To resolve this apparent discrepancy, detailed kinetic studies were conducted with cellotetraose. Only exoglucanase activity was detected. The function of this enzyme in V. cholerae remains to be determined, especially because our strain of this organism does not utilize cellobiose.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				M. Qi, H.-S. Jun, and C. W. Forsberg Cel9D, an Atypical 1,4-{beta}-D-Glucan Glucohydrolase from Fibrobacter succinogenes: Characteristics, Catalytic Residues, and Synergistic Interactions with Other Cellulases J. Bacteriol., March 15, 2008; 190(6): 1976 - 1984. [Abstract] [Full Text] [PDF]

				D. E. Hunt, D. Gevers, N. M. Vahora, and M. F. Polz Conservation of the Chitin Utilization Pathway in the Vibrionaceae Appl. Envir. Microbiol., January 1, 2008; 74(1): 44 - 51. [Abstract] [Full Text] [PDF]

				K. L. Meibom, X. B. Li, A. T. Nielsen, C.-Y. Wu, S. Roseman, and G. K. Schoolnik The Vibrio cholerae chitin utilization program PNAS, February 24, 2004; 101(8): 2524 - 2529. [Abstract] [Full Text] [PDF]

				X. Li and S. Roseman The chitinolytic cascade in Vibrios is regulated by chitin oligosaccharides and a two-component chitin catabolic sensor/kinase PNAS, January 13, 2004; 101(2): 627 - 631. [Abstract] [Full Text] [PDF]