Objective  Identification and characteristics of Hsp70 family in Setosphaeria turcica were studied to facilitate elucidating their roles in the growth, development, and pathogenicity of the microbe.

  Methods  Members of StHsp70 family were identified from the S. turcica genome database. Physicochemical properties, subcellular localization, phylogenetic evolution, conserved motifs, and domains of the genes analyzed by bioinformatics methods.

  Results  Eleven members, StHsp70-1 to StHsp70-11, were identified from the database. Most of them were predicated to locate in the cytoplasmic as well as in endoplasmic reticulum, mitochondrial, and nucleus in lesser amounts. The phylogenetic analysis divided the members into 7 categories including Classes A−F that showed a high homology with the heat shock proteins SSA, SSB, SSC, KAR2, SSE, and SSZ of Saccharomyces cerevisiae, respectively, and Class G that had none with what were found in yeasts. All StHsp70s contained conserved motif 5, but motif 6 existed in Class A−D only. Class G had only motifs 2−4 making the class significantly different from the others. The variations in subcellular localization might be the reason of the significant N-terminal differences in the NBD domains of the Hsp70 classes of S. turcica from those of yeast. Whereas the considerably varied C-terminal structure and extensibility among the classes, especially on the StHsp70s of Class G, might contribute to the diversity of substrates.

  Conclusion  The 11 members of Hsp70 family of S. turcica could be divided into 7 classes with 4 members in Class G being significantly different from the others in physicochemical properties and structure. It indicated that the genes were of multifunctional molecular chaperones.