The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus
Joint Authors
Source
Issue
Vol. 2012, Issue 2012 (31 Dec. 2012), pp.1-7, 7 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2012-06-06
Country of Publication
Egypt
No. of Pages
7
Main Subjects
Abstract EN
A highly conserved arginine residue is close to the catalytic center of PPM/PP2C-type protein phosphatases.
Different crystal structures of PPM/PP2C homologues revealed that the guanidinium side chain of this arginine residue can adopt variable conformations and may bind ligands, suggesting an important role of this residue during catalysis.
In this paper, we randomly mutated Arginine 13 of tPphA, a PPM/PP2C-type phosphatase from Thermosynechococcus elongatus, and obtained 18 different amino acid variants.
The generated variants were tested towards p-nitrophenyl phosphate and various phosphopeptides.
Towards p-nitrophenyl phosphate as substrate, twelve variants showed 3–7 times higher Km values than wild-type tPphA and four variants (R13D, R13F, R13L, and R13W) completely lost activity.
Strikingly, these variants were still able to dephosphorylate phosphopeptides, although with strongly reduced activity.
The specific inability of some Arg-13 variants to hydrolyze p-nitrophenyl phosphate highlights the importance of additional substrate interactions apart from the substrate phosphate for catalysis.
The properties of the R13 variants indicate that this residue assists in substrate binding.
American Psychological Association (APA)
Su, Jiyong& Forchhammer, Karl. 2012. The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus. Enzyme Research،Vol. 2012, no. 2012, pp.1-7.
https://search.emarefa.net/detail/BIM-459306
Modern Language Association (MLA)
Su, Jiyong& Forchhammer, Karl. The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus. Enzyme Research No. 2012 (2012), pp.1-7.
https://search.emarefa.net/detail/BIM-459306
American Medical Association (AMA)
Su, Jiyong& Forchhammer, Karl. The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus. Enzyme Research. 2012. Vol. 2012, no. 2012, pp.1-7.
https://search.emarefa.net/detail/BIM-459306
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-459306