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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Research » Publications at this Location » Publication #126871
Title: THE GLUCOMANNOKINASE OF THE GRAM-NEGATIVE RUMINAL BACTERIUM,PREVOTELLA BRYANTII B14, AND ITS SEQUENCE CONSERVATION WITH REGULATORY GLUCOKINASES OF GRAM-POSITIVE BACTERIA

Author
item FIELDS, M - CORNELL UNIVERSITY
item Russell, James

Submitted to: Anaerobe
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2002
Publication Date: 9/27/2002
Citation: FIELDS, M.W., RUSSELL, J.B. 2002. THE DNA SEQUENCE OF A PREVOTELLA BRYANTII B14 GLUCOMANNOKINASE AND ITS HOMOLOGY TO THE REGULATORY GLUCOKINASES OF GRAM-POSITIVE BACTERIA. ANAEROBE. 8:69-74.

Interpretive Summary: Ruminant animals have bacteria that can digest fiber and other plant polymers, but fiber digestion is rarely greater than 50%. The enzymes responsible for fiber digestion have not been well characterized, and little was known about their regulation. Previous work indicated that Prevotella bryantii could regulate its enzyme production via the activity of its sugar kinase, an enzyme involved in sugar utilization. We determine the amino acid sequence of the sugar kinase, and used this information to clone the gene encoding this enzyme. It was found that this glucokinase was similar to a class of regulatory glucokinase from other, non-ruminant bacteria. This type of information on the genomics of ruminal bacterial enzymes will lead to improvements in the efficiency of fiber digestion in cattle.

Technical Abstract: The glucomannokinase gene of Prevotella bryantii B14 (GenBank accession #AF326962), a gram-negative ruminal bacterium, was amplified with degenerate PCR primers that corresponded to the N-terminal amino acid residues of the purified glucomannokinase and the C-termini of other bacterial glucokinases. One of the PCR products had the correct size (approximately 60% of the entire sequence), and the PCR product corresponded to the N-terminus of the purified P. bryantii B14 glucomannokinase. Genetic studies indicate that some gram-positive bacteria have regulatory glucokinases that are involved in catabolite repression, and previous work with P. bryantii B14 indicated that the glucomannokinase played a role in b-glucanase transcription. Sequence comparisons indicated that regulatory and non-regulatory bacterial glucokinases formed two distinct clusters. The amino acid sequences within nthe regulatory and non-regulatory glucokinases groups had mean similarity values of 42 plus/minus 2.4% and 35 plus/minus 2.0%, respectively, but the mean similarity value between the two groups was only 17 plus/minus 2.0%. These results indicate that the regulatory glucokinases were more closely related to each other compared to other bacterial glucokinases. The mechanism of regulation is not known, but sequence comparisons suggested that a common theme might exist among the regulatory sugar kinases. This is the first report of regulatory glucokinase sequence from of a gram-negative, strictly anaerobic bacterium.