Download MendeleyProbing the Active Site of Class 3 L-Asparaginase by Mutagenesis: Mutations of the Ser-Lys Tandems of ReAV.
Pokrywka, K., Grzechowiak, M., Sliwiak, J., Worsztynowicz, P., Loch, J.I., Ruszkowski, M., Gilski, M., Jaskolski, M.(2025) Biomolecules 15
- PubMed: 40723816
- DOI: https://doi.org/10.3390/biom15070944
- Primary Citation of Related Structures:
9QCT, 9QCU, 9QCW, 9QCY, 9QCZ - PubMed Abstract:
The ReAV enzyme from Rhizobium etli , a representative of Class 3 L-asparaginases, is sequentially and structurally different from other known L-asparaginases. This distinctiveness makes ReAV a candidate for novel antileukemic therapies. ReAV is a homodimeric protein, with each subunit containing a highly specific zinc-binding site created by two cysteines, a lysine, and a water molecule. Two Ser-Lys tandems (Ser48-Lys51, Ser80-Lys263) are located in the close proximity of the metal binding site, with Ser48 hypothesized to be the catalytic nucleophile. To further investigate the catalytic process of ReAV, site-directed mutagenesis was employed to introduce alanine substitutions at residues from the Ser-Lys tandems and at Arg47, located near the Ser48-Lys51 tandem. These mutational studies, along with enzymatic assays and X-ray structure determinations, demonstrated that substitution of each of these highly conserved residues abolished the catalytic activity, confirming their essential role in enzyme mechanism.
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
Organizational Affiliation:
