Khramtsov N V, Blunt D S, Montelone B A, Upton S J
Division of Biology, Kansas State University, Manhattan 66506, USA.
J Parasitol. 1996 Jun;82(3):423-7.
We determined the nucleotide (nt) sequence of the putative gene encoding acetyl-coenzyme A synthetase (ACS) from the parasitic protozoan Cryptosporidium parvum. The gene is single copy, located on a chromosome of approximately 1.08 mb, and has no introns. The gene is characterized by low codon usage bias and encodes a 694-amino acid (aa) protein with a predicted molecular size of 78 kDa, similar to other ACSs from different prokaryotic and eukaryotic species. Comparison of multiple protein alignments of ACSs revealed a new conserved sequence motif PKT(R/V/L)SGK(I/V/T)(T/M/V/K)R(R/N) near the C-terminus, which may be a signature for ACSs. This motif shares significant homology with sequences from other members of the AMP-binding family, has secondary structure similar to the purine-binding motif of ATP- and GTP-ases, and may play a role in the enzymatic activity of proteins from the AMP-binding family.
我们确定了来自寄生原生动物微小隐孢子虫的假定编码乙酰辅酶A合成酶（ACS）基因的核苷酸（nt）序列。该基因是单拷贝的，位于一条约1.08兆碱基的染色体上，且无内含子。该基因的特点是密码子使用偏好性低，编码一个694个氨基酸（aa）的蛋白质，预测分子大小为78 kDa，与来自不同原核生物和真核生物物种的其他ACS相似。对ACS的多个蛋白质比对结果显示，在C端附近有一个新的保守序列基序PKT(R/V/L)SGK(I/V/T)(T/M/V/K)R(R/N)，这可能是ACS的一个特征标记。该基序与AMP结合家族其他成员的序列具有显著同源性，具有与ATP和GTP酶的嘌呤结合基序相似的二级结构，可能在AMP结合家族蛋白质的酶活性中发挥作用。
