2wm3

Structural highlights

Function

[NMRL1_HUMAN] Redox sensor protein. Undergoes restructuring and subcellular redistribution in response to changes in intracellular NADPH/NADP(+) levels. At low NADPH concentrations the protein is found mainly as a monomer, and binds argininosuccinate synthase (ASS1), the enzyme involved in nitric oxide synthesis. Association with ASS1 impairs its activity and reduces the production of nitric oxide, which subsecuently prevents apoptosis. Under normal NADPH concentrations, the protein is found as a dimer and hides the binding site for ASS1. The homodimer binds one molecule of NADPH. Has higher affinity for NADPH than for NADP(+). Binding to NADPH is necessary to form a stable dimer.^{[1] [2] [3]}

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

References

1. ↑ Zhao Y, Zhang J, Li H, Li Y, Ren J, Luo M, Zheng X. An NADPH sensor protein (HSCARG) down-regulates nitric oxide synthesis by association with argininosuccinate synthetase and is essential for epithelial cell viability. J Biol Chem. 2008 Apr 18;283(16):11004-13. doi: 10.1074/jbc.M708697200. Epub 2008, Feb 8. PMID:18263583 doi:http://dx.doi.org/10.1074/jbc.M708697200
2. ↑ Zheng X, Dai X, Zhao Y, Chen Q, Lu F, Yao D, Yu Q, Liu X, Zhang C, Gu X, Luo M. Restructuring of the dinucleotide-binding fold in an NADP(H) sensor protein. Proc Natl Acad Sci U S A. 2007 May 22;104(21):8809-14. Epub 2007 May 11. PMID:17496144
3. ↑ Dai X, Li Y, Meng G, Yao S, Zhao Y, Yu Q, Zhang J, Luo M, Zheng X. NADPH is an allosteric regulator of HSCARG. J Mol Biol. 2009 Apr 17;387(5):1277-85. Epub 2009 Feb 28. PMID:19254724 doi:10.1016/j.jmb.2009.02.049