3TZW: Crystal Structure Of A Fragment Containing The Acyltransferase Domain Of Pks13 From Mycobacterium Tuberculosis In The Orthorhombic Apoform At 2.6 A

Pks13 is a type I polyketide synthase involved in the final biosynthesis step of mycolic acids, virulence factors, and essential components of the Mycobacterium tuberculosis envelope. Here, we report the biochemical and structural characterization of a 52-kDa fragment containing the acyltransferase domain of Pks13. This fragment retains the ability to load atypical extender units, unusually long chain acyl-CoA with a predilection for carboxylated substrates. High resolution crystal structures were determined for the apo, palmitoylated, and carboxypalmitoylated forms. Structural conservation with type I polyketide synthases and related fatty-acid synthases also extends to the interdomain connections. Subtle changes could be identified both in the active site and in the upstream and downstream linkers in line with the organization displayed by this singular polyketide synthase. More importantly, the crystallographic analysis illustrated for the first time how a long saturated chain can fit in the core structure of an acyltransferase domain through a dedicated channel. The structures also revealed the unexpected binding of a 12-mer peptide that might provide insight into domain-domain interaction.
PDB ID: 3TZWDownload
MMDB ID: 102360
PDB Deposition Date: 2011/9/28
Updated in MMDB: 2012/10
Experimental Method:
x-ray diffraction
Resolution: 2.6  Å
Source Organism:
Mycobacterium tuberculosis
Similar Structures:
Biological Unit for 3TZW: dimeric; determined by author and by software (PISA)
Molecular Components in 3TZW
Label Count Molecule
Proteins (2 molecules)
Polyketide Synthase Pks13
Molecule annotation
12-mer Peptide
Molecule annotation
Chemicals (11 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB