Species specific substrates and products choices of 4-O-acetyltransferase from Trichoderma brevicompactum

Publication date: Available online 3 June 2017 Source:Enzyme and Microbial Technology Author(s): Shikha Sharma, Indu Kumari, Razak Hussain, Mushtaq Ahmed, Yusuf Akhter The antagonistic species of Trichoderma such as T.harzianum, T.viride, T.virens and T.koningii are well-known biocontrol agents that have been reported to suppress pathogenic soil microbes and enhance the growth of crop plants. Secondary metabolites (SMs) including trichothecenes are responsible for its biocontrol activities. The trichothecenes, trichodermin and harzianum A (HA) are produced in species dependent manner respectively, by Trichoderma brevicompactum (TB) and Trichoderma arundinaceum (TA). The last step in the pathway involves the conversion of trichodermol into trichodermin or HA alternatively, which is catalyzed by 4-O-acetyltransferase (encoded by tri3 gene). Comparative sequence analysis of acetyltransferase enzyme of TB with other chloramphenicol acetyltransferase (CAT) family proteins revealed the conserved motif involved in catalysis. Multiple substrate binding studies were carried out to explore the mechanism behind the two different outcomes. His188 was found to have a role in initial substrate binding. In the case of trichodermin synthesis, represented by ternary complex 1, the trichodermol and acetic anhydride (AAn), the two substrates come very close to each other during molecular simulation analysis so that interactions become possible between them and acetyl group may get transf...
Source: Enzyme and Microbial Technology - Category: Biotechnology Source Type: research