Crystal structure of carboxypeptidase G2, a bacterial enzyme with applications in cancer therapy.
Rowsell, S., Pauptit, R.A., Tucker, A.D., Melton, R.G., Blow, D.M., Brick, P.(1997) Structure 5: 337-347
- PubMed: 9083113 
- DOI: https://doi.org/10.1016/s0969-2126(97)00191-3
- Primary Citation of Related Structures:  
1CG2 - PubMed Abstract: 
Carboxypeptidase G enzymes hydrolyze the C-terminal glutamate moiety from folic acid and its analogues, such as methotrexate. The enzyme studied here, carboxypeptidase G2 (CPG2), is a dimeric zinc-dependent exopeptidase produced by Pseudomonas sp. strain RS-16. CPG2 has applications in cancer therapy: following its administration as an immunoconjugate, in which CPG2 is linked to an antibody to a tumour-specific antigen, it can enzymatically convert subsequently administered inactive prodrugs to cytotoxic drugs selectively at the tumour site. CPG2 has no significant amino acid sequence homology with proteins of known structure. Hence, structure determination of CPG2 was undertaken to identify active-site residues, which may in turn provide ideas for protein and/or substrate modification with a view to improving its therapeutic usefulness.
Organizational Affiliation: 
Blackett Laboratory, Imperial College London, SW7 2BZ, UK.