Structure and Substrate Recognition of the Bottromycin Maturation Enzyme BotP

Area of Science:

• Biochemistry
• Molecular Biology
• Natural Product Synthesis

Background:

• Bottromycins are potent antimicrobial peptides effective against Gram-positive bacteria, including MRSA.
• These compounds are ribosomally synthesized and post-translationally modified peptides (RiPPs).
• The bottromycin precursor peptide (BotA) uniquely features a C-terminal follower sequence.

Purpose of the Study:

• To structurally and biochemically characterize BotP, a leucyl-aminopeptidase-like enzyme from the bottromycin pathway.
• To elucidate the function of BotP in the bottromycin biosynthesis process.
• To provide insights for targeted modification of bottromycins.

Main Methods:

• Enzyme purification and activity assays.
• X-ray crystallography to determine apo BotP and Mn²⁺-bound BotP structures.
• Computational modeling of a BotP/substrate complex.

Main Results:

• BotP was identified as the enzyme responsible for removing the N-terminal methionine from the BotA precursor peptide.
• Crystal structures revealed the enzyme's active site and facilitated modeling of substrate interaction.
• The characterization provides a foundation for understanding substrate recognition and enzyme mechanism.

Conclusions:

• BotP plays a crucial role in bottromycin precursor processing.
• Structural and biochemical data offer a mechanistic basis for BotP's function.
• This work is a foundational step towards engineering bottromycins with enhanced antibiotic properties.