The Evolutionary Analysis Of Heat Shock Proteins And Algorithms For The Classification Their Families

Heat shock proteins(Hsps)are a class of proteins synthesized by organisms as responses to physiological and environmental stressful conditions and have a strong protective effect on the cells.By analyzing the distribution of the heat shock protein 90(Hsp90)subfamily in the genome,the existing results for the interspecies distribution of Hsp90 subfamily were proved.The 90 A subfamily is present in all species except bacteria.There is no obvious rule for the distribution of 90 B and TRAP1 subfamilies.The 90 C subfamily exists only in plants,and most of the Htp G subfamilies exist in bacteria.The subcellular organelles of Hsp90 were analyzed by performing subcellular localization predictions.It was found that Hsp90 are widely distributed in cell.However,the distribution of each subfamily of Hsp90 demonstrates its own preferences.By performing sequence alignment,81 genes of Hsps were identified in four species of gramineous plants.The collinearity analysis of these genes demonstrated that the sequence similarity of Hsps from the same family was higher than that from other familes.The statistical results of synonymous substitution rate of each family of Hsps in gramineous plants indicate that except for heat shock protein 60,the rates of evolution of other families are slower than those of gramineous plants.The phylogenetic tree and the conserved domains of Hsps were analyzed by using the software MEGA.We found that Hsp70,Hsp90 and Hsp100 are highly conserved.The local phylogenetic tree of Hsp90 families and Hsp100 families of sorghum and rice were constructed.The results showed that the genetic relationship within the species was closer than that among species.A support vector machine(SVM)based method was proposed for the classification of plant heat shock proteins,in which the protein sequences were encoded by using the Reduced Amino Acid Alphabet(RAAA).In the jackknife test,the method yielded an accuracy of 93.65% for classifying the six families of heat shock proteins in plant.This result indicates that the method will be an effective tool for plant Hsps classification.