Sivaji Manigandan, Sadasivam Vinoth, Narayanasamy Jayabalan, Samuel Selvaraj, Fan Chuanzhu
Department of Plant Science, Bharathidasan University, Tiruchirappalli, India.
Department of Plant Science, Bharathidasan University, Tiruchirappalli, India; Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America.
PLoS One. 2014 Mar 17;9(3):e91915. doi: 10.1371/journal.pone.0091915. eCollection 2014.
Chitinase proteins have evolved and diversified almost in all organisms ranging from prokaryotes to eukaryotes. During evolution, internal repeats may appear in amino acid sequences of proteins which alter the structural and functional features. Here we deciphered the internal repeats from Chitinase and characterized the structural similarities between them. Out of 24 diverse Chitinase sequences selected, six sequences (2CJL, 2DSK, 2XVP, 2Z37, 3EBV and 3HBE) did not contain any internal repeats of amino acid sequences. Ten sequences contained repeats of length <50, and the remaining 8 sequences contained repeat length between 50 and 100 residues. Two Chitinase sequences, 1ITX and 3SIM, were found to be structurally similar when analyzed using secondary structure of Chitinase from secondary and 3-Dimensional structure database of Protein Data Bank. Internal repeats of 3N17 and 1O6I were also involved in the ligand-binding site of those Chitinase proteins, respectively. Our analyses enhance our understanding towards the identification of structural characteristics of internal repeats in Chitinase proteins.
几丁质酶蛋白几乎在从原核生物到真核生物的所有生物体中都经历了进化和多样化。在进化过程中，蛋白质的氨基酸序列可能会出现内部重复，从而改变其结构和功能特征。在此，我们解析了几丁质酶的内部重复序列，并对它们之间的结构相似性进行了表征。在所选择的24种不同的几丁质酶序列中，有6个序列（2CJL、2DSK、2XVP、2Z37、3EBV和3HBE）不包含任何氨基酸序列的内部重复。10个序列包含长度小于50的重复，其余8个序列包含长度在50至100个残基之间的重复。当使用蛋白质数据银行二级和三维结构数据库中的几丁质酶二级结构进行分析时，发现两个几丁质酶序列1ITX和3SIM在结构上相似。3N17和1O6I的内部重复也分别参与了这些几丁质酶蛋白的配体结合位点。我们的分析增进了我们对几丁质酶蛋白内部重复结构特征识别的理解。
