Isupov M N, Fleming T M, Dalby A R, Crowhurst G S, Bourne P C, Littlechild J A
Schools of Chemistry and Biological Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
J Mol Biol. 1999 Aug 20;291(3):651-60. doi: 10.1006/jmbi.1999.3003.
The enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from the archaea shows low sequence identity (16-20%) with its eubacterial and eukaryotic counterparts. The crystal structure of the apo GAPDH from Sulfolobus solfataricus has been determined by multiple isomorphous replacement at 2.05 A resolution. The enzyme has several differences in secondary structure when compared with eubacterial GAPDHs, with an overall increase in the number of alpha-helices. There is a relocation of the active-site residues within the catalytic domain of the enzyme. The thermostability of the S. solfataricus enzyme can be attributed to a combination of an ion pair cluster and an intrasubunit disulphide bond.
古生菌的3-磷酸甘油醛脱氢酶（GAPDH）与真细菌和真核生物中的对应酶相比，序列同源性较低（16-20%）。嗜热栖热菌脱辅基GAPDH的晶体结构已通过多对同晶置换法在2.05 Å分辨率下测定。与真细菌GAPDH相比，该酶在二级结构上有若干差异，α-螺旋数量总体增加。酶催化结构域内的活性位点残基发生了重新定位。嗜热栖热菌酶的热稳定性可归因于离子对簇和亚基内二硫键的共同作用。
