Interaction of Hsp70 Ssb1 and atypical Hsp70 Ssz1

Our goal was to better understand the interaction between the Hsp70 Ssb1 and the atypical Hsp70 Ssz1, which we had uncovered by in vivo site-specific Bpa crosslinking. Ssz1 having Bpa incorporated was purified and incubated with purified Ssb1 and the J-domain protein Zuo1 during activation of photo cross-linking. After protein gel electrophoresis and protease digestion of excised bands, the resulting cross-linked peptides were analyzed by mass spectrometry and identified by StavroX.