Structural investigation of the docking domain assembly from trans-AT polyketide synthases.

Docking domains (DDs) located at the C- and N-termini of polypeptides play a crucial role in directing the assembly of polyketide synthases (PKSs), which are multienzyme complexes. Here, we determined the crystal structure of a complex comprising the C-terminal DD (DD) and N-terminal DD (DD) of macrolactin trans-acyltransferase (AT) PKS that were fused to a functional enzyme, AmpC EC2 β-lactamase. Interface analyses of the DD/DD complex revealed the molecular intricacies in the core section underpinning the precise DD assembly.

Characterization of the extended substrate spectrum of the class A β-lactamase CESS-1 from Stenotrophomonas sp. and structure-based investigation into its substrate preference.

Objectives: Stenotrophomonas spp. intrinsically resistant to many β-lactam antibiotics are found throughout the environment. CESS-1 identified in Stenotrophomonas sp.