1887

Abstract

Malate synthase is one of the key enzymes of the glyoxylate cycle and is essential for growth on acetate as sole carbon source. The gene from , encoding malate synthase, was isolated, subcloned and expressed in and Sequencing of a 3024 bp DNA fragment containing the gene revealed that it is located close to the isocitrate lyase gene The two genes are separated by 597 bp and are transcribed in divergent directions. The predicted gene product consists of 739 amino acids with an of 82362. Interestingly, this polypeptide shows only weak identity with malate synthase polypeptides from other organisms and possesses an extra N-terminal sequence of about 170 amino acid residues. Inactivation of the chromosomal gene led to the absence of malate synthase activity and to the inability to grow on acetate, suggesting that only one malate synthase is present in The malate synthase was purified from an -overexpressing strain and biochemically characterized. The native enzyme was shown to be a monomer migrating at an of about 80000. By sequencing the N-terminus of malate synthase the predicted translational start site of the enzyme was confirmed. The enzyme displayed values of 30 μM and 12 μM for the substrates glyoxylate and acetyl CoA, respectively. Oxalate, glycolate and ATP were found to be inhibitors of malate synthase activity. The present study provides evidence that the malate synthase from is functionally similar to other malate synthase enzymes but is different both in size and primary structure.

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/content/journal/micro/10.1099/13500872-140-11-3099
1994-11-01
2019-08-17
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http://instance.metastore.ingenta.com/content/journal/micro/10.1099/13500872-140-11-3099
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