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Clathrin-coated vesicles (CCVs) play critical roles in multiple cellular processes, including nutrient uptake, endosome/lysosome biogenesis, pathogen invasion, regulation of signalling receptors, etc. Saccharomyces cerevisiae Ent5 ( Sc Ent5) is one of the two major adaptors supporting the CCV-mediated TGN/endosome traffic in yeast cells. However, the classification and phosphoinositide binding characteristic of Sc Ent5 remain elusive. Here we report the crystal structures of the Sc Ent5 N-terminal domain, and find that Sc Ent5 contains an insertion α′ helix that does not exist in other ENTH or ANTH domains. Furthermore, we investigate the classification of Sc Ent5-N 31−191 by evolutionary history analyses and structure comparisons, and find that the Sc Ent5 N-terminal domain shows different phosphoinositide binding property from r Epsin1 and r CALM. Above results facilitate the understanding of the Sc Ent5-mediated vesicle coat formation process. [ABSTRACT FROM AUTHOR]

The versatility of Hsp90 can be attributed to the variety of co-chaperone proteins that modulate the role of Hsp90 in many cellular processes. As a co-chaperone of Hsp90, Cpr7 is essential for accelerating the cell growth in an Hsp90-containing trimeric complex. Here, we report the crystal structure of Cpr7 at a resolution of 1.8 Å. It consists of an N-terminal PPI domain and a C-terminal TPR domain, and exhibits a U-shape conformation. Our studies revealed the aggregation state of Cpr7 in solution and the interaction properties between Cpr7 and the MEEVD sequence from the C-terminus of Hsp90. In addition, the structure and sequence analysis between Cpr7 and homologues revealed the structure basis both for the function differences between Cpr6 and Cpr7 and the functional complements between Cns1 and Cpr7. Our studies facilitate the understanding of Cpr7 and provide decent insights into the molecular mechanisms of the Hsp90 co-chaperone pathway. [ABSTRACT FROM AUTHOR]