Bacterial elongation factor Tu (EF-Tu) is a model monomeric G protein composed of three covalently linked domains. Previously, we evaluated the contributions of individual domains to the thermostability of EF-Tu from the thermophilic bacterium Bacillus stearothermophilus. We showed that domain 1 (G-domain) sets up the basal level of thermostability for the whole protein. Here we chose to locate the thermostability determinants distinguishing the thermophilic domain 1 from a mesophilic domain 1. By an approach of systematically swapping protein regions differing between G-domains from mesophilic Bacillus subtilis and thermophilic B. stearothermophilus, we demonstrate that a small portion of the protein, the N-terminal 12 amino acid residues, plays a key role in the thermostability of this domain. We suggest that the thermostabilizing effect of the N-terminal region could be mediated by stabilizing the functionally important effector region. Finally, we demonstrate that the effect of the N-terminal region is significant also for the thermostability of the full-length EF-Tu. Study holds ProTherm entries: 25745, 25746, 25747, 25748, 25749, 25750, 25751, 25752, 25753, 25754, 25755, 25756, 25757, 25758, 25759, 25760, 25761, 25762, 25763, 25764, 25765, 25766, 25767, 25768, 25769, 25770 Extra Details: G domain; EF-Tu in GDP form Thermostability; G protein; EF-Tu; G-domain; Bacillus
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:56 p.m.
|Number of data points||26|
|Proteins||Elongation factor Tu|
|Assays/Quantities/Protocols||Experimental Assay: Tm|
|Libraries||Mutations for sequence MAKAKFERTKPHVNIGTIGHVDHGKTTLTAAITTVLAKQGKAEAKAYDQIDAAPEERERGITISTAHVEYETEARHYAHVDCPGHADYVKNMITGAAQMDGAILVVSAADGPMPQTREHILLSRQVGVPYIVVFLNKCDMVDDEELLELVEMEVRDLLSEYDFPGDEVPVIKGSALKALEGDPKWEEKIIELMNAVDEYIPTPQREVDKPFMMPIEDVFSITGRGTVATGRVERGTLKVGDPVEIIGLSDEPKATTVTGVEMFRKLLDQAEAGDNIGALLRGVSRDEVERGQVLAKPGSITPHTKFKAQVYVLTKEEGGRHTPFFSNYRPQFYFRTTDVTGIITLPEGVEMVMPGDNVEMTVELIAPIAIEEGTKFSIREGGRTVGAGSVSEIIE|