Identification of a novel operon in Lactococcus lactis encoding three enzymes for lactic acid synthesis: phosphofructokinase, pyruvate kinase, and lactate dehydrogenase

Llanos, Roxana M.; Harris, Civonnia; Hillier, Alan J.; Davidson, Barrie E.

doi:10.1128/jb.175.9.2541-2551.1993

Cited by 77 publications

(70 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As reported here, an ldh homologue lies just downstream of nox in S. pyogenes. The significance of this observation is unknown; however, it is not unusual for genes encoding enzymes with interdependent activities to lie in close proximity to one another in a genome (28).…”

Section: S Pyogenes Contains a Single Nox Homologue But Lacks Nprmentioning

confidence: 99%

Contribution of NADH Oxidase to Aerobic Metabolism of Streptococcus pyogenes

et al. 2000

View full text Add to dashboard Cite

The gram-positive microorganism Streptococcus pyogenes (group A streptococcus) is the causative agent of numerous infections of the skin and pharynx ranging from superficial diseases including erysipelas, impetigo, and pharyngitis to those characterized by extensive tissue destruction, such as necrotizing fasciitis. The initial stage of all streptococcal infections involves the attachment of the organism to epithelial cells of the nasopharynx or epidermis (49), and considerable evidence suggests that the ability to sense an aerobic environment and survive plays an important role in this process (17,47,48). A good example of this is streptococcal fibronectin-binding protein F, which is regulated in response to oxidative stress (16,48).The mechanisms and gene products that allow S. pyogenes to survive in aerobic environments remain largely unknown. While S. pyogenes produces a single Mn-containing superoxide dismutase (SOD) that is essential for aerobic streptococcal growth (16), it lacks many of the proteins known to be important for aerobic growth. Since the lactic acid bacteria (including those in the genera Streptococcus, Enterococcus, and Lactococcus) cannot synthesize heme (11), S. pyogenes lacks the catalases and cytochrome oxidases required for oxidative energy-linked metabolism and instead depends on substrate level phosphorylation for growth. In addition, streptococci lack the moderate-to-high levels of intracellular glutathione found in gram-negative bacteria (12). Without such mechanisms for handling oxidative stress, it seems that aerobic conditions should severely restrict streptococcal growth, yet O 2 seems to have a positive effect on the growth yields of some other lactic acid bacteria (25,30). This suggests the existence of other enzymes that are important for aerobic streptococcal growth.Recently, other lactic acid bacteria have been found to contain unique flavoproteins involved in oxidative metabolism that are very different from the respiratory redox enzymes of cytochrome-containing bacteria like Escherichia coli (8,20,41,42). One such flavoprotein, NADH peroxidase (NPXase), has been characterized extensively in Enterococcus faecalis, where it uses H 2 O 2 as an electron acceptor, thereby providing an enzymatic defense against peroxide stress (41). Another E. faecalis flavoprotein, NADH oxidase (NOXase), catalyzes the direct four-electron reduction of O 2 to water and serves as an electron acceptor during active aerobic metabolism in this organism (42). These two flavoproteins have 44% amino acid identity to one another, with the most highly conserved segments containing the nonflavin redox center and the flavin adenine dinucleotide (FAD)-and NADH-binding regions. The nonflavin redox center in each of these enzymes is an unusual stabilized cysteine-sulfenic acid that cycles between oxidized and reduced states (33).A role for these two flavoproteins in facilitating the aerobic metabolism of lactic acid bacteria may require the regeneration of one NAD ϩ molecule by NPXase, and the regeneration ...

show abstract

Section: S Pyogenes Contains a Single Nox Homologue But Lacks Nprmentioning

confidence: 99%

Contribution of NADH Oxidase to Aerobic Metabolism of Streptococcus pyogenes

et al. 2000

View full text Add to dashboard Cite

show abstract

“…2), indicating that S. bovis Idh has a monocistronic mode of transcription. In Lactococcus lactis, Idh is a part of the las operon which encodes phosphofructokinase, pyruvate kinase and LDH (Llanos et al, 1992(Llanos et al, , 1993. In Bifidobacterium longum (Minowa et al, 1989) and Pediococcus acidilactici (Garmyn et al,1995), the promoter is located at the position close to the 5' end of the Idh, and a putative transcriptional terminator exists downstream of the 3' end, suggesting that the transcription is monocistronic.…”

Section: Cloning Of S Bovis Ldh Genementioning

confidence: 99%

Regulation of lactate dehydrogenase synthesis in a ruminal bacterium, Streptococcus bovis.

Asanuma

Iwamoto

Hino

1997

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

Lactate dehydrogenase (LDH) was purified from three strains of Streptococcus bovis, and the gene Idh was cloned and sequenced. The Idh of S. bovis from a goat (TH1) was different from the Idhs of two other strains from cattle (TH2, JB1) in that Asp220 was substituted for Glu. Northern blot analysis revealed that the LDH-mRNA of S. bovis was approximately 1.0 kbp, which was transcribed in a monocistronic fashion. When cells were grown at pH 6.9 in a batch culture, the level of Idh transcript decreased as the growth phase changed; from exponential growth to the cessation of growth. The level of Idh transcript was higher in cells grown at pH 4.5 than at pH 6.9. This observation was consistent with the amounts of LDH in cells and the percentages of lactate produced. These results support the hypothesis that S. bovis regulates LDH synthesis at the transcriptional level probably in response to intracellular pH.

show abstract

“…$ On the basis of the nucleotide sequences ofgap (this study), tpi (Cancilla et al, 1995) and the las operon (Llanos et al, 1993). §On the basis of the nucleotide sequences of lacABCDFEG (de Vos eta/., 1990;van Rooijen et al, 1991).…”

mentioning

confidence: 99%

Lactococcus lactis glyceraldehyde-3-phosphate dehydrogenase gene, gap: further evidence for strongly biased codon usage in glycolytic pathway genes

Cancilla

Hillier²,

Davidson³

1995

Microbiology

View full text Add to dashboard Cite

The gene gap, encoding glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12), was isolated from a genomic library of Lactococcus lactis LM0230 DNA. Plasmids containing the L. lactis gene were able to complement a gap mutant of Escherichia coli. The nucleotide sequence of gap predicted a polypeptide chain of 337 amino acids for the enzyme and a subunit molecular mass of 36043. The codon usage in gap and four other glycolytic genes from L. lactis showed a high degree of bias, when compared with 84 other chromosomal genes. Northern blot analysis of total L. lactis RNA showed that gap hybridized strongly with a 1.3 kb transcript. The 5' end of the transcript was determined by primer extension analysis to be a C located 35 bp upstream from the gap start codon. These transcript analyses, and the orientation of the open reading frames in the DNA flanking gap, indicated that in L. lactis gap is expressed on a monocistronic transcript. Nucleotide sequencing indicated that the DNA adjacent to gap did not encode other glycolytic pathway enzymes. The DNA sequence flanking gap contained two open reading frames (ORF156 and ORF211) of unknown function. The 3' end of a clpA homologue was identified in the sequence upstream of ORFl56. The location of gap on the L. lactis D L l l chromosome map was determined to be between map coordinates 0.530 and 0660.

show abstract

Identification of a novel operon in Lactococcus lactis encoding three enzymes for lactic acid synthesis: phosphofructokinase, pyruvate kinase, and lactate dehydrogenase

Cited by 77 publications

References 50 publications

Contribution of NADH Oxidase to Aerobic Metabolism of Streptococcus pyogenes

Contribution of NADH Oxidase to Aerobic Metabolism of Streptococcus pyogenes

Regulation of lactate dehydrogenase synthesis in a ruminal bacterium, Streptococcus bovis.

Lactococcus lactis glyceraldehyde-3-phosphate dehydrogenase gene, gap: further evidence for strongly biased codon usage in glycolytic pathway genes

Contact Info

Product

Resources

About