JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Brochu, D.
Right arrow Articles by Vadeboncoeur, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Brochu, D.
Right arrow Articles by Vadeboncoeur, C.

Journal of Bacteriology, February 1999, p. 709-717, Vol. 181, No. 3
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

The HPr(Ser) Kinase of Streptococcus salivarius: Purification, Properties, and Cloning of the hprK Gene

Denis Brochu and Christian Vadeboncoeur*

GREB, Département de Biochimie, Faculté des Sciences et de Génie and Faculté de Médecine Dentaire, GREB, Université Laval, Ste-Foy, Québec, Canada G1K 7P4

Received 3 September 1998/Accepted 9 November 1998

In gram-positive bacteria, HPr, a protein of the phosphoenolpyruvate:sugar phosphotransferase system, is phosphorylated on a serine residue at position 46 by an ATP-dependent protein kinase. The HPr(Ser) kinase of Streptococcus salivarius ATCC 25975 was purified, and the encoding gene (hprK) was cloned by using a nucleotide probe designed from the N-terminal amino acid sequence. The predicted amino acid sequence of the S. salivarius enzyme showed 45% identity with the Bacillus subtilis enzyme, the conserved residues being located mainly in the C-terminal half of the protein. The predicted hprK gene product has a molecular mass of 34,440 Da and a pI of 5.6. These values agree well with those found experimentally by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, molecular sieve chromatography in the presence of guanidine hydrochloride, and chromatofocusing using the purified protein. The native protein migrates on a Superdex 200 HR column as a 330,000-Da protein, suggesting that the HPr(Ser) kinase is a decamer. The enzyme requires Mg2+ for activity and functions optimally at pH 7.5. Unlike the enzyme from other gram-positive bacteria, the HPr(Ser) kinase from S. salivarius is not stimulated by FDP or other glycolytic intermediates. The enzyme is inhibited by inorganic phosphate, and its Kms for HPr and ATP are 31 µM and 1 mM, respectively.

* Corresponding author. Mailing address: GREB, Université Laval, Ste-Foy, Québec, Canada G1K 7P4. Phone: (418) 656-2319. Fax: (418) 656-2861. E-mail: Christian.Vadeboncoeur{at}bcm.ulaval.ca.

Journal of Bacteriology, February 1999, p. 709-717, Vol. 181, No. 3
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1999 by the American Society for Microbiology. All rights reserved.