The universal ancestor was a thermophile or a hyperthermophile

被引:34
作者
Di Giulio, M
机构
[1] CNR, Int Inst Genet & Biophys, I-80125 Naples, Italy
[2] Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA
基金
美国国家科学基金会;
关键词
paralogous protein; thermophily index; ancestral sequence; last universal common ancestor; origin of life;
D O I
10.1016/S0378-1119(01)00781-8
中图分类号
Q3 [遗传学];
学科分类号
071007 ; 090102 ;
摘要
By exploiting the correlation between the optimal growth temperature of organisms and a thermophily index based on the propensity of amino acids to enter thermophile/hyperthermophile proteins. an analysis is conducted in order to establish whether the last universal common ancestor (LUCA) was a mesophile or a (hyper)thermophile. This objective is reached by using maximum parsimony and maximum likelihood to reconstruct the ancestral sequences of the LUCA for two pairs of sets of paralogous protein sequences by means of the phylogenetic tree topology derived from the small subunit ribosomal RNA, even if this is rooted in all three possible ways. The thermophily index of all the reconstructed ancestral sequences of the LUCA belongs to the set of the thermophile/hyperthermophile sequences, thus supporting the hypotheses that see the LUCA as a thermophile or a hyperthermophile. (C) 2001 Elsevier Science B.V. All rights reserved.
引用
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页码:11 / 17
页数:7
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