Phosphatase Superfamily Cys-based III
Phosphatase Classification: Superfamily Cys-based III
This superfamily has a unique fold, but shares the common CX5R catalytic motif with another two cysteine-based superfamilies, superfamily Cys-based I and superfamily Cys-based II.
The superfamily consists of two member families present in human low molecular weight PTP (LWMPTP) and SSU72. Despite having only 15% sequence identity, human LMWPTP and SSU72 structures superimpose with an rmsd of 1.7 Å [1].
A third family, arsenate reductase (ArsC) [2], is only found in prokaryotes. While known to reduce arsenate to arsenite (a similar reaction to the phosphatase reaction), the B. subtilis gene also has in vitro phosphatase activity. A different phosphatase fold, CDC25/Rhodanese also has members in plants and yeast (ACR2) that are capable of arsenate reductase activity, highlighting the similarity of the protein phosphatase and arsenate reductase activities.
Reference
- Zhang Y, Zhang M, and Zhang Y. Crystal structure of Ssu72, an essential eukaryotic phosphatase specific for the C-terminal domain of RNA polymerase II, in complex with a transition state analogue. Biochem J. 2011 Mar 15;434(3):435-44. DOI:10.1042/BJ20101471 |
- Bennett MS, Guan Z, Laurberg M, and Su XD. Bacillus subtilis arsenate reductase is structurally and functionally similar to low molecular weight protein tyrosine phosphatases. Proc Natl Acad Sci U S A. 2001 Nov 20;98(24):13577-82. DOI:10.1073/pnas.241397198 |
