InterPro domain: IPR029009

This superfamily represents a domain found at the N terminus of the L-serine dehydratases beta chain and in some but not all D-3-phosphoglycerate dehydrogenases (PGDH) and related enzymes.

This domain superfamily covers the intervening domain (also known as the allosteric substrate binding domain) found in D-3-phosphoglycerate dehydrogenase (PGDH) from Mycobacterium tuberculosis [ 1 ]. The intervening domain, which serves as an anion binding site, is located between the substrate-binding domain and the regulatory domain (L-serine binding) [ 2 , 2 , 3 ]. The intervening domain may be an allosteric site for the control of enzyme activity [ 4 ]. Interestingly, the intervening domain is found in PGDH from bacteria such as Mycobacterium, Bacillus subtilis, Corynebacterium, plants such as Arabidopsis, and higher order eukaryotes, including mammals. This domain is not present in the PGDH from E. coli and some lower eukaryotes, such as yeast and Neurospora [ 4 ].

L-serine dehydratase is found as a heterodimer of alpha and beta chain or as a fusion of the two chains in a single protein. This domain is found in the beta chain. Similar to PGDH, this domain may serve as a noncatalytic site for L-serine [ 5 ].

1. A novel mechanism for substrate inhibition in Mycobacterium tuberculosis D-3-phosphoglycerate dehydrogenase. J. Biol. Chem. 282, 31517-24
2. Role of the anion-binding site in catalysis and regulation of Mycobacterium tuberculosis D-3-phosphoglycerate dehydrogenase. Biochemistry 48, 4808-15
3. Contrasting catalytic and allosteric mechanisms for phosphoglycerate dehydrogenases. Arch. Biochem. Biophys. 519, 175-85
4. Crystal structure of Mycobacterium tuberculosis D-3-phosphoglycerate dehydrogenase: extreme asymmetry in a tetramer of identical subunits. J. Biol. Chem. 280, 14892-9
5. Kinetic evidence of a noncatalytic substrate binding site that regulates activity in Legionella pneumophila L-serine dehydratase. Biochemistry 51, 6961-7