3ASB: Crystal Structure Of Plp-Bound Ll-Diaminopimelate Aminotransferase From Chlamydia Trachomatis

We have previously reported the structures of the native holo and substrate-bound forms of ll-diaminopimelate aminotransferase from Arabidopsis thaliana (AtDAP-AT). Here, we report the crystal and molecular structures of the ll-diaminopimelate aminotransferase from Chlamydia trachomatis (CtDAP-AT) in the apo-form and the pyridoxal-5'-phosphate-bound form. The molecular structure of CtDAP-AT shows that its overall fold is essentially identical with that of AtDAP-AT except that CtDAP-AT adopts an "open" conformation as opposed to the "closed" conformation of AtDAP-AT. Although AtDAP-AT and CtDAP-AT are approximately 40% identical in their primary sequence, they have major differences in their substrate specificities; AtDAP-AT is highly specific for LL-DAP, whereas CtDAP-AT accepts a wider range of substrates. Since all of the residues involved in substrate recognition are highly conserved between AtDAP-AT and CtDAP-AT, we propose that differences in flexibility of the loops lining the active-site region between the two enzymes likely account for the differences in substrate specificity.
PDB ID: 3ASBDownload
MMDB ID: 93248
PDB Deposition Date: 2010/12/10
Updated in MMDB: 2011/09
Experimental Method:
x-ray diffraction
Resolution: 2.7  Å
Source Organism:
Similar Structures:
Biological Unit for 3ASB: dimeric; determined by author and by software (PISA)
Molecular Components in 3ASB
Label Count Molecule
Proteins (2 molecules)
Ll-diaminopimelate Aminotransferase(Gene symbol: aspC)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB