Ydj1 but not Sis1 stabilizes Hsp70 protein under prolonged stress in vitro

Yeast cytosol has two important co‐chaperons; Ydj1 and Sis1. Genetic experiments showed that Ydj1 is not essential for viability; however, cells lacking it grow very poorly at 30°C or unable to grow at extreme temperatures. On the other hand, Sis1 is an essential protein and apparently plays a functional role at assembly or disassembly of protein complexes. Stability experiments revealed that only Ydj1‐protected Hsp70 proteins can hydrolyze ATP under prolonged stress. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 171–174, 2008. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com