Identification of a gene cluster encoding Krebs cycle oxidative enzymes linked to the pyruvate carboxylase gene in Lactococcus lactis ssp. lactis C2 1,2

H. Wang, K. A. Baldwin, D. J. O'Sullivan, L. L. McKay

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

We identified a 14-kb pyruvate carboxylase gene-containing fragment from a lactococcal C2-lambda phage genomic library. Downstream of the pyruvate carboxylase gene-containing fragment, a gene cluster coding for open reading frames displaying extensive homology to citrate synthase, aconitase, and a truncated isocitrate dehydrogenase was identified. However, the truncation was shown to have occurred during the cloning by two noncontiguous Sau3AI fragments ligating together. The lactococcal citrate synthase gene consisted of 1323 bp and encoded a 441-amino acid citrate synthase protein. The lactococcal aconitase gene was 2544 bp and encoded an 848-amino acid protein. Corresponding to the complete citrate synthase gene, citrate synthase activity was detected in Lactococcus lactis ssp. lactis C2. Isocitrate dehydrogenase activity was found to be missing in Lactococcus lactis C2, suggesting that the gene may be incomplete or is not expressed, resulting in a requirement for glutamic acid in lactococci.

Original languageEnglish (US)
Pages (from-to)1912-1918
Number of pages7
JournalJournal of Dairy Science
Volume83
Issue number9
DOIs
StatePublished - Sep 2000

Bibliographical note

Funding Information:
This research was supported, in part, by the Minnesota-South Dakota Dairy Foods Research Center, St. Paul, MN; Dairy Management Inc., Rosemont, IL; a National Institute of General Medical Sciences (NIGMS) Training Grant in Biotechnology; and the Kraft General Foods Chair in Food Science.

Keywords

  • Aconitase
  • Citrate synthase
  • Isocitrate dehydrogenase
  • Lactococci

Fingerprint Dive into the research topics of 'Identification of a gene cluster encoding Krebs cycle oxidative enzymes linked to the pyruvate carboxylase gene in Lactococcus lactis ssp. lactis C2 1,2'. Together they form a unique fingerprint.

Cite this