Phosphoglycerate Mutase Is a Highly Efficient Enzyme without Flux Control in Lactococcus lactis
Artikel i vetenskaplig tidskrift, 2010

The glycolytic enzyme phosphoglycerate mutase (PGM), which catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate, was examined in Lactococcus lactis with respect to its function, kinetics and glycolytic flux control. A library of strains with PGM activities ranging between 15-465% of the wild-type level was constructed by replacing the native promoter of pgm with synthetic promoters of varying strengths. The specific growth rate and glucose flux were found to be maximal at the wild-type level at which PGM had no flux control. Low flux control of PGM was found on mixed acid fluxes at highly reduced PGM activities. At the wild-type level PGM operated very far from V-max. Consequently, in a strain with only 15% PGM activity, the catalytic rate of PGM was almost six times higher than in the wildtype. K-m of PGM for 3-phosphoglycerate was 1.0 m M and k(cat) was 3,200 s(-1). The L. lactis PGM was dependent on 2,3-bisphosphoglyceric acid for activity, which showed that the enzyme is of the dPGM type in accordance with its predicted homology to dPGM enzymes from other organisms. In conclusion, PGM from L. lactis is a highly efficient catalyst, which partially explains why this enzyme has limited control in wild-type L. lactis. Copyright (C) 2010 S. Karger AG, Basel

glycolytic flux

Metabolic control analysis

Lactic acid bacteria

Glycolysis

escherichia-coli

Metabolism

expression

no control

il1403

Systems biology

dehydrogenase

Phosphoglycerate mutase

Författare

C. Solem

Danmarks Tekniske Universitet (DTU)

Dina Petranovic Nielsen

Chalmers, Kemi- och bioteknik, Livsvetenskaper, Systembiologi

B. Koebmann

Danmarks Tekniske Universitet (DTU)

I. Mijakovic

Microbiologie de l'Alimentation au Service de la Sante Humaine

P. R. Jensen

Danmarks Tekniske Universitet (DTU)

Journal of Molecular Microbiology and Biotechnology

1464-1801 (ISSN) 1475-3774 (eISSN)

Vol. 18 174-180

Ämneskategorier

Industriell bioteknik

DOI

10.1159/000315458