Publications

• Purification and characterization of S-adenosylhomocysteine deaminase from streptonigrin-producing Streptomyces flocculus.

  Zulty J.J., Speedie M.K.

  An S-adenosylhomocysteine deaminase has been isolated and purified from streptonigrin-producing Streptomyces flocculus ATCC 13257. Deamination represents the major metabolic route of S-adenosylhomocysteine in this organism. The protein was found to be monomeric with a molecular weight of 56,100 +/ ... >> More

  An S-adenosylhomocysteine deaminase has been isolated and purified from streptonigrin-producing Streptomyces flocculus ATCC 13257. Deamination represents the major metabolic route of S-adenosylhomocysteine in this organism. The protein was found to be monomeric with a molecular weight of 56,100 +/-1,600. The activity was optimal at pH 7.0 and 37 degrees C, and the deaminase was inactivated by p-chloromercuribenzoate but not by metal chelators. The Km for S-adenosylhomocysteine is 2.5 mM, and the Ki for inhibition by deoxycoformycin is 1.6 nM. << Less

  J Bacteriol 171:6840-6844(1989) [PubMed] [EuropePMC]

• Structure-based activity prediction for an enzyme of unknown function.

  Hermann J.C., Marti-Arbona R., Fedorov A.A., Fedorov E., Almo S.C., Shoichet B.K., Raushel F.M.

  With many genomes sequenced, a pressing challenge in biology is predicting the function of the proteins that the genes encode. When proteins are unrelated to others of known activity, bioinformatics inference for function becomes problematic. It would thus be useful to interrogate protein structur ... >> More

  With many genomes sequenced, a pressing challenge in biology is predicting the function of the proteins that the genes encode. When proteins are unrelated to others of known activity, bioinformatics inference for function becomes problematic. It would thus be useful to interrogate protein structures for function directly. Here, we predict the function of an enzyme of unknown activity, Tm0936 from Thermotoga maritima, by docking high-energy intermediate forms of thousands of candidate metabolites. The docking hit list was dominated by adenine analogues, which appeared to undergo C6-deamination. Four of these, including 5-methylthioadenosine and S-adenosylhomocysteine (SAH), were tested as substrates, and three had substantial catalytic rate constants (10(5) M(-1 )s(-1)). The X-ray crystal structure of the complex between Tm0936 and the product resulting from the deamination of SAH, S-inosylhomocysteine, was determined, and it corresponded closely to the predicted structure. The deaminated products can be further metabolized by T. maritima in a previously uncharacterized SAH degradation pathway. Structure-based docking with high-energy forms of potential substrates may be a useful tool to annotate enzymes for function. << Less

  Nature 448:775-779(2007) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.