PROSITE: PDOC00066 (documentation)

{PDOC00066} {PS00068; MDH} {BEGIN} ********************************************** * Malate dehydrogenase active site signature * **********************************************

Malate dehydrogenase (EC 1.1.1.37) (MDH) [1,2] catalyzes the interconversion of malate to oxaloacetate utilizing the NAD/NADH cofactor system. The enzyme participates in the citric acid cycle and exists in all aerobics organisms. While prokaryotic organisms contains a single form of MDH, in eukaryotic cells there are two isozymes: one which is located in the mitochondrial matrix and the other in the cytoplasm. Fungi and plants also harbor a glyoxysomal form which functions in the glyoxylate pathway. In plants chloroplast there is an additional NADP-dependent form of MDH (EC 1.1.1.82) which is essential for both the universal C3 photosynthesis (Calvin) cycle and the more specialized C4 cycle. As a signature pattern for this enzyme we have chosen a region that includes two residues involved in the catalytic mechanism [3]: an aspartic acid which is involved in a proton relay mechanism, and an arginine which binds the substrate. -Consensus pattern: [LIVM]-T-[TRKMN]-L-D-x(2)-R-[STA]-x(3)-[LIVMFY] [D and R are the active site residues] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in SWISS-PROT: NONE. -Note: MDH from archaebacteria do not belong to the above family; they are evolutionary related to lactate dehydrogenases [4]. -Last update: November 1995 / Text revised. [ 1] McAlister-Henn L. Trends Biochem. Sci. 13:178-181(1988). [ 2] Gietl C. Biochim. Biophys. Acta 1100:217-234(1992). [ 3] Birktoft J.J., Rhodes G., Banaszak L.J. Biochemistry 28:6065-6081(1989). [ 4] Cendrin F., Chroboczek J., Zaccai G., Eisenberg H., Mevarech M. Biochemistry 32:4308-4313(1993). {END} ---------------------------------------------------------------------------- If you have problems or comments... [Image] Back to the ExPASy molecular biology server home page