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Crystal structure of a trimeric archaeal adenylate kinase from the mesophile Methanococcus maripaludis with an unusually broad functional range and thermal stability
Author(s) -
Davlieva Milya,
Shamoo Yousif
Publication year - 2009
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.22549
Subject(s) - methanococcus , thermostability , thermophile , hyperthermophile , mesophile , archaea , adenylate kinase , chemistry , enzyme , crystallography , biology , biochemistry , bacteria , genetics , gene
The structure of the trimeric adenylate kinase from the Archaebacteria Methanococcus mariplaludis (AK MAR ) has been solved to 2.5‐Å resolution and the temperature dependent stability and kinetics of the enzyme measured. The K M and V max of AK MAR exhibit only modest temperature dependence from 30°–60°C. Although M. mariplaludis is a mesophile with a maximum growth temperature of 43°C, AK MAR has a very broad functional range and stability (T m = 74.0°C) that are more consistent with a thermophilic enzyme with high thermostability and exceptional activity over a wide range of temperatures, suggesting that this microbe may have only recently invaded a mesophilic niche and has yet to fully adapt. A comparison of the Local Structural Entropy (LSE) for AK MAR to the related adenylate kinases from the mesophile Methanococcus voltae and thermophile Methanococcus thermolithotrophicus show that changes in LSE are able to fully account for the intermediate stability of AK MAR and highlights a general mechanism for protein adaptation in this class of enzymes. Proteins 2010. © 2009 Wiley‐Liss, Inc.