Li de La Sierra-Gallay Ines, Collinet Bruno, Graille Marc, Quevillon-Cheruel Sophie, Liger Dominique, Minard Philippe, Blondeau Karine, Henckes Gilles, Aufrère Robert, Leulliot Nicolas, Zhou Cong-Zhao, Sorel Isabelle, Ferrer Jean-Luc, Poupon Anne, Janin Joël, van Tilbeurgh Herman
Laboratoire d'Enzymologie et Biochimie Structurales (CNRS-UPR 9063), Bât. 34, 1 Av. de la Terrasse, 91198 Gif sur Yvette, France.
Proteins. 2004 Mar 1;54(4):776-83. doi: 10.1002/prot.10596.
The protein product of the YGR205w gene of Saccharomyces cerevisiae was targeted as part of our yeast structural genomics project. YGR205w codes for a small (290 amino acids) protein with unknown structure and function. The only recognizable sequence feature is the presence of a Walker A motif (P loop) indicating a possible nucleotide binding/converting function. We determined the three-dimensional crystal structure of Se-methionine substituted protein using multiple anomalous diffraction. The structure revealed a well known mononucleotide fold and strong resemblance to the structure of small metabolite phosphorylating enzymes such as pantothenate and phosphoribulo kinase. Biochemical experiments show that YGR205w binds specifically ATP and, less tightly, ADP. The structure also revealed the presence of two bound sulphate ions, occupying opposite niches in a canyon that corresponds to the active site of the protein. One sulphate is bound to the P-loop in a position that corresponds to the position of beta-phosphate in mononucleotide protein ATP complex, suggesting the protein is indeed a kinase. The nature of the phosphate accepting substrate remains to be determined.
作为我们酵母结构基因组学项目的一部分，酿酒酵母YGR205w基因的蛋白质产物成为了研究对象。YGR205w编码一种小蛋白（290个氨基酸），其结构和功能未知。唯一可识别的序列特征是存在沃克A基序（P环），这表明它可能具有核苷酸结合/转化功能。我们使用多波长反常散射法测定了硒代甲硫氨酸取代蛋白的三维晶体结构。该结构显示出一种众所周知的单核苷酸折叠，并且与泛酸激酶和磷酸核糖激酶等小代谢物磷酸化酶的结构有很强的相似性。生化实验表明，YGR205w特异性结合ATP，对ADP的结合则较弱。该结构还显示存在两个结合的硫酸根离子，它们占据了对应于该蛋白质活性位点的峡谷中相对的位置。其中一个硫酸根与P环结合，其位置与单核苷酸蛋白ATP复合物中β-磷酸的位置相对应，这表明该蛋白质确实是一种激酶。磷酸接受底物的性质还有待确定。
