3NE3: Mycobacterium Tuberculosis Acyl Carrier Protein Synthase Apo Structure

Citation:
Abstract
The crystal structures of acyl carrier protein synthase (AcpS) from Mycobacterium tuberculosis (Mtb) and Corynebacterium ammoniagenes determined at pH 5.3 and pH 6.5, respectively, are reported. Comparison of the Mtb apo-AcpS structure with the recently reported structure of the Mtb AcpS-ADP complex revealed that AcpS adopts two different conformations: the orthorhombic and trigonal space-group structures show structural differences in the alpha2 helix and in the conformation of the alpha3-alpha4 connecting loop, which is in a closed conformation. The apo-AcpS structure shows electron density for the entire model and was obtained at lower pH values (4.4-6.0). In contrast, at a higher pH value (6.5) AcpS undergoes significant conformational changes, resulting in disordered regions that show no electron density in the AcpS model. The solved structures also reveal that C. ammoniagenes AcpS undergoes structural rearrangement in two regions, similar to the recently reported Mtb AcpS-ADP complex structure. In vitro reconstitution experiments show that AcpS has a higher post-translational modification activity between pH 4.4 and 6.0 than at pH values above 6.5, where the activity drops owing to the change in conformation. The results show that apo-AcpS and AcpS-ADP adopt different conformations depending upon the pH conditions of the crystallization solution.
PDB ID: 3NE3Download
MMDB ID: 83694
PDB Deposition Date: 2010/6/8
Updated in MMDB: 2012/08
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 3NE3: monomeric; determined by author
Molecular Components in 3NE3
Label Count Molecule
Protein (1 molecule)
1
Holo-[acyl-carrier-protein] Synthase
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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