Structural determinants increasing flexibility confer cold adaptation in psychrophilic phosphoglycerate kinase
Structural determinants increasing flexibility confer cold adaptation in psychrophilic phosphoglycerate kinase
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DOI：
10.1007/s00792-019-01102-x
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发表时间：
2019-05
期刊：
影响因子：
2.9
通讯作者：
D. Mandelman;L. Ballut;David A. Wolff;G. Feller;C. Gerday;R. Haser;N. Aghajari
中科院分区：
文献类型：
--
作者：
D. Mandelman;L. Ballut;David A. Wolff;G. Feller;C. Gerday;R. Haser;N. Aghajari
用X射线晶体学方法测定了嗜冷假单胞菌TACII 18的磷酸甘油酸激酶（PGK）的晶体结构，并与嗜温、嗜热和超嗜热的对应物进行了比较。PGK是一种双结构域酶，经历大结构域运动以催化从1，3-二磷酸甘油酸和ADP产生ATP。而构象动力学维持这种铰链弯曲酶的催化机制，现在似乎相当清楚，决定因素，在低温下的高催化效率，这嗜冷PGK是未知的。三维结构的比较表明，这种酶已经带来了多个（全球和本地）的具体适应。总之，这些存在于冷适应PGK的总体增加的柔性中，从而允许更好地接近活性位点，但也存在于嗜冷酶的潜在更无序的过渡状态中，这是由于一些催化残基的不稳定。
Crystal structures of phosphoglycerate kinase (PGK) from the psychrophilePseudomonas sp. TACII 18 have been determined at high resolution by X-ray crystallography methods and compared with mesophilic, thermophilic and hyperthermophilic counterparts. PGK is a two-domain enzyme undergoing large domain movements to catalyze the production of ATP from 1,3-biphosphoglycerate and ADP. Whereas the conformational dynamics sustaining the catalytic mechanism of this hinge-bending enzyme now seems rather clear, the determinants which underlie high catalytic efficiency at low temperatures of this psychrophilic PGK were unknown. The comparison of the three-dimensional structures shows that multiple (global and local) specific adaptations have been brought about by this enzyme. Together, these reside in an overall increased flexibility of the cold-adapted PGK thereby allowing a better accessibility to the active site, but also a potentially more disordered transition state of the psychrophilic enzyme, due to the destabilization of some catalytic residues.