Lysine 71 of the chaperone protein Hsc70 is essential for ATP hydrolysis
Lysine 71 of the chaperone protein Hsc70 is essential for ATP hydrolysis
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DOI：
10.1074/jbc.271.27.15874
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发表时间：
1996-07-05
影响因子：
4.8
通讯作者：
McKay, DB
中科院分区：
文献类型：
--
作者：
OBrien, MC;Flaherty, KM;McKay, DB
已经提出，牛70-kDa热休克同源蛋白的赖氨酸71可能通过稳定H2O分子或OH-离子对核苷酸的γ-磷酸进行亲核攻击而参与ATP水解的催化（Flaherty，K，M.，Wilbanks，S，M，DeLuca-Flaherty，C.，McKay，D. B，（1994）J，Biol. Chem，12899-12907; Wilbanks，S，M，DeLuca-Flaherty，C，和McKay，D，B.（1994）J. Biol. Chem，269，12893-12898）。为了检验这一假设，将ATP酶片段70-kDa热休克同源蛋白的赖氨酸71突变为谷氨酸、甲硫氨酸和丙氨酸;并且已经确定了突变蛋白的动力学和结构性质。所有三种突变蛋白都缺乏可测量的ATP水解活性。突变蛋白质的晶体结构已被确定为1.7埃的分辨率;所有三个核苷酸结合位点都有ATP。这些数据将赖氨酸71鉴定为ATP化学水解所必需的残基。
It has been proposed that lysine 71 of the bovine 70-kDa heat shock cognate protein might participate in catalysis of ATP hydrolysis by stabilizing an H2O molecule or an OH- ion for nucleophilic attack on the gamma-phosphate of the nucleotide (Flaherty, K, M., Wilbanks, S, M,, DeLuca-Flaherty, C., and McKay, D. B, (1994) J, Biol. Chem, 12899-12907; Wilbanks, S, M,, DeLuca-Flaherty, C,, and McKay, D, B. (1994) J. Biol. Chem, 269, 12893-12898), To test this hypothesis, lysine 71 of the ATPase fragment 70-kDa heat shock cognate protein has been mutated to glutamic acid, methionine, and alanine; and the kinetic and structural properties of the mutantproteins have been determined. All three mutant proteins are devoid of measurable ATP hydrolysis activity. Crystal structures of the mutant proteins have bben determined to a resolution of 1.7 Angstrom; all three have ATP in the nucleotide binding site. These data identify lysine 71 as a residue that is essential for chemical hydrolysis of ATP.