Structures of ternary complexes of aspartate semialdehyde dehydrogenase Rv3708c from Mycobacterium tuberculosis H37Rv

resolution and in complex with S methyl l cysteine sulfoxide SMCS and sulfate at 1.95 A resolution. The overall structure of Mtb ASADH is similar to those of its orthologues. However, in the Mtb ASADH glycerol complex structure the glycerol molecule is noncovalently bound to the active site residue Cys130, while in the Mtb ASADH SMCS complex structure the SMCS Cys is covalently linked to Cys130. The Mtb ASADH SMCS complex structurally mimics one of the intermediate steps in the proposed mechanism of ASADH enzyme catalysis. Comparison of the two complex structures revealed that the amino acids Glu224 and Arg249 undergo conformational changes upon binding of glycerol. Moreover, the structures reported here may help in the development of species specific antibacterial drug molecules against human pathogen