4R2N: Crystal Structure Of Rv3772 In Complex With Its Substrate

Aminotransferases of subfamily Ibeta, which include histidinol phosphate aminotransferases (HspATs) and aromatic amino acid aminotransferases (ArATs), are structurally similar but possess distinct substrate specificities. This study, encompassing structural and biochemical characterisation of HspAT and ArAT from Mycobacterium tuberculosis demonstrates that the residues lining the substrate binding pocket and N-terminal lid are the primary determinants of their substrate specificities. In mHspAT, hydrophilic residues in the substrate binding pocket and N-terminal lid allow the entry and binding of its preferential substrate, Hsp. On the other hand, the hydrophobic nature of both the substrate binding pocket and the N-terminal lid of mArAT is responsible for the discrimination of a polar substrate such as Hsp, while facilitating the binding of Phe and other aromatic residues such as Tyr and Trp. In addition, the present study delineates the ligand induced conformational rearrangements, providing insights into the plasticity of aminotransferases. Furthermore, the study also demonstrates that the adventitiously bound ligand 2-(N-morpholino)ethanesulfonic acid (MES) is indeed a specific inhibitor of HspAT. These results suggest that previously untapped morpholine-ring scaffold compounds could be explored for the design of new anti-TB agents.
PDB ID: 4R2NDownload
MMDB ID: 131614
PDB Deposition Date: 2014/8/12
Updated in MMDB: 2016/12
Experimental Method:
x-ray diffraction
Resolution: 1.98  Å
Source Organism:
Similar Structures:
Biological Unit for 4R2N: dimeric; determined by author and by software (PISA)
Molecular Components in 4R2N
Label Count Molecule
Proteins (2 molecules)
Putative Phenylalanine Aminotransferase
Molecule annotation
Chemicals (7 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB