Pseudomonas testosteroni ketosteroid isomerase

A 3-Ketosteroid isomerase (3-KSI). This enz)mie catalyses the allylic isomerization of the 5,6 double bond of A5-3-ketosteroids to the 4,5 position by stereospecific intramolecular transfer of a proton. The enz)mie has been isolated from bacteria, and especially the 3-KSIs from Comamoms testosteroni and Pseudomonas putida have been investigated (Smith et al, 1980). The gene coding for the 3-KSI of Pseudomonas putida biot) e B has been cloned and its nucleotide sequence determined (Kim et al, 1994). 

K. S. Kim, W. Lee, K. Y. Choi, and B.-H. Oh, Crystal structure of delta A -3-ketosteroid isomerase from pseudomonas testosteroni in complex with equilenin settles the correct hydrogen bonding scheme for transition state stabilization, J. Biol. Chem. 274, 32863-32868 (1999). (e) T. K. Manojkumar, C. Cui, and K. S. Kim, Theoretical insights into the mechanism of acetylcholinesterase-catalyzed acylation of acetylcholine, J. Comput. Chem. 26, 606-611... 

An analogous approach has been used to inactivate the A -3-ketosteroid isom-erase (steroid A-isomerase) from Pseudomonas testosteroni, an enzyme which... 

S. Yun, D.S. Jang, D.-H. Kim, K.Y. Choi, H.C. Lee, N NMR relaxation studies of backbone dynamics in free and steroid-bound Delta 5-3-ketosteroid isomerase from Pseudomonas testosteroni. Biochemistry 40 (2001) 3967-3973. 

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