Expression, purification and crystallization of enterococcus faecium streptogramin A acetyltransferase

Area of Science:

• Biochemistry
• Structural Biology
• Crystallography

Background:

• Streptogramin A acetyltransferase is an enzyme found in Enterococcus faecium.
• Understanding its structure is crucial for antibiotic development.

Purpose of the Study:

• To overexpress, purify, and crystallize the streptogramin A acetyltransferase from Enterococcus faecium.
• To determine the crystal structures of the enzyme.

Main Methods:

• Overexpression in Escherichia coli.
• Protein purification.
• Hanging-drop vapor-diffusion method for crystallization.
• X-ray diffraction analysis.

Main Results:

• Two distinct crystal forms (Form I and Form II) were obtained.
• Form I crystals diffract to 2.5 A (space group P2(1)2(1)2(1)).
• Form II crystals diffract to 2.7 A (space group F222).
• Analysis suggests one copy of the trimeric enzyme in Form I and two copies in Form II per asymmetric unit.

Conclusions:

• The successful crystallization of streptogramin A acetyltransferase provides a basis for further structural studies.
• These findings contribute to understanding the enzyme's role and potential inhibition.
• The distinct crystal forms offer opportunities for detailed structural investigations.