Cloning, expression, purification, crystallization and preliminary X-ray analysis of peptidyl-tRNA hydrolase from...

Area of Science:

• Biochemistry
• Structural Biology
• Crystallography

Background:

• Peptidyl-tRNA hydrolase (PTH) is crucial for protein synthesis fidelity.
• It cleaves ester bonds in detached peptidyl-tRNAs, preventing ribosomal stalling.

Purpose of the Study:

• To determine the crystal structures of Mycobacterium tuberculosis Peptidyl-tRNA hydrolase.
• To elucidate the structural basis of enzyme activity and substrate interaction.

Main Methods:

• Crystallization of Mycobacterium tuberculosis Peptidyl-tRNA hydrolase in three distinct crystal forms.
• Collection of X-ray diffraction data for each crystal form.
• Analysis of unit-cell parameters for P2(1)2(1)2(1) and P2(1) space groups.

Main Results:

• Successfully crystallized the enzyme in three related but distinct polymorphic forms.
• Characterized the unit-cell parameters for each crystalline form: P2(1)2(1)2(1) [a = 36.30, b = 61.85, c = 73.97 A] and P2(1) [a = 35.83, b = 73.79, c = 59.79 A, beta = 92.3 degrees].
• A second P2(1)2(1)2(1) form was also identified with parameters a = 35.84, b = 57.06, c = 72.59 A.

Conclusions:

• The crystallization of Peptidyl-tRNA hydrolase in multiple forms provides opportunities for detailed structural analysis.
• These distinct crystal structures are essential for understanding the enzyme's mechanism and for potential drug development targeting Mycobacterium tuberculosis.