Psychrophilic Elongation Factor Tu from the Antarctic Moraxella sp. Tac II 25: Biochemical Characterization and Cloning of the Encoding Gene
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- 作者：Mariorosario Masullo ; Paolo Arcari ; Barbara de Paola ; Andrea Parmeggiani ; and Vincenzo Bocchini
- 刊名：Biochemistry
- 出版年：2000
- 出版时间：December 19, 2000
- 年：2000
- 卷：39
- 期：50
- 页码：15531 - 15539
- 全文大小：223K
- 年卷期：v.39,no.50(December 19, 2000)
- ISSN：1520-4995
文摘
The elongation factor Tu was isolated from a psychrophilic eubacterial Antarctic Moraxellastrain (MoEF-Tu) and its molecular and functional properties were determined. It catalyzed the synthesisof poly(Phe) and bound specifically guanine nucleotides with an affinity for GDP about 12-fold higherthan that for GTP. The affinity toward guanine nucleotides was lower than that of other eubacterial EF-Tu. The intrinsic GTPase activity of MoEF-Tu was hardly detectable but was accelerated by 2 orders ofmagnitude in the presence of the antibiotic kirromycin (GTPasek). Such a property resembled Escherichiacoli EF-Tu (EcEF-Tu) even though the affinity of MoEF-Tu for the antibiotic was lower. MoEF-Tu showeda thermophilicity higher than that of EcEF-Tu; its temperature for half-denaturation was 44 
C. The MoEF-Tu encoding gene corresponding to E. coli tufA was cloned and sequenced. The translated protein had acalculated molecular weight of 43 288 and contained the GTP-binding sequence motifs. Concerning itsprimary structure, MoEF-Tu showed sequence identity with E. coli and Thermus thermophilus EF-Tuequal to 84% and 74%, respectively, while the identity with EF-1
from the archaeon Sulfolobus solfataricuswas equal to 32%.
C. The MoEF-Tu encoding gene corresponding to E. coli tufA was cloned and sequenced. The translated protein had acalculated molecular weight of 43 288 and contained the GTP-binding sequence motifs. Concerning itsprimary structure, MoEF-Tu showed sequence identity with E. coli and Thermus thermophilus EF-Tuequal to 84% and 74%, respectively, while the identity with EF-1 from the archaeon Sulfolobus solfataricuswas equal to 32%.