Point mutation of V252 in neomycin C epimerase enlarges substrate-binding pocket and improves neomycin B accumulation in Streptomyces fradiae.

ABSTRACT: Neomycin, an aminoglycoside antibiotic with broad-spectrum antibacterial resistance, is widely used in pharmaceutical and agricultural fields. However, separation and purification of neomycin B as an active substance from Streptomyces fradiae are complicated. Although NeoN can catalyze conversion of neomycin C to neomycin B, the underlying catalytic mechanism is still unclear. In this study, the genomic information of high-yielding mutant S. fradiae SF-2 was elucidated using whole-genome sequencing. Subsequently, the mechanism of NeoN in catalyzing conversion of neomycin C to neomycin B was resolved based on NeoN-SAM-neomycin C ternary complex. Mutant NeoN^V252A showed improved NeoN activity, and the recombinant strain SF-2-NeoN^V252A accumulated 16,766.6 U/mL neomycin

SUBMITTER: Li X 

PROVIDER: S-EPMC10991966 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature