Structural studies reveal flexible roof of active site responsible for ?-transaminase CrmG overcoming by-product inhibition.

ABSTRACT: Amine compounds biosynthesis using ?-transaminases has received considerable attention in the pharmaceutical industry. However, the application of ?-transaminases was hampered by the fundamental challenge of severe by-product inhibition. Here, we report that ?-transaminase CrmG from Actinoalloteichus cyanogriseus WH1-2216-6 is insensitive to inhibition from by-product ?-ketoglutarate or pyruvate. Combined with structural and QM/MM studies, we establish the detailed catalytic mechanism for CrmG. Our structural and biochemical studies reveal that the roof of the active site in PMP-bound CrmG is flexible, which will facilitate the PMP or by-product to dissociate from PMP-bound CrmG. Our results also show that amino acceptor caerulomycin M (CRM M), but not ?-ketoglutarate or pyruvate, can form strong interactions with the roof of the active site in PMP-bound CrmG. Based on our results, we propose that the flexible roof of the active site in PMP-bound CrmG may facilitate CrmG to overcome inhibition from the by-product.

SUBMITTER: Xu J 

PROVIDER: S-EPMC7438487 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature