The structure of rabbit muscle phosphoglucomutase at intermediate resolution.

Area of Science:

• Biochemistry
• Structural Biology
• Enzymology

Background:

• Phosphoglucomutase is a key enzyme in carbohydrate metabolism.
• Understanding its structure is crucial for elucidating its catalytic mechanism.

Purpose of the Study:

• To determine the three-dimensional structure of rabbit phosphoglucomutase.
• To provide insights into the enzyme's active site and substrate binding.

Main Methods:

• X-ray crystallography at 2.7 A resolution.
• Isomorphous and molecular replacement techniques.
• Heavy atom positioning using vector search and difference Fourier methods.

Main Results:

• The structure reveals a four-domain alpha/beta fold.
• Two molecules form a dimer, arranging into fibers along crystallographic axes.
• The active site is located in a deep crevice between domains, binding phosphoserine and substrate residues.

Conclusions:

• The determined structure provides a detailed atomic model of rabbit phosphoglucomutase.
• Insights into the active site architecture suggest a mechanism for substrate binding and catalysis.