Functional analysis of Arabidopsis thaliana BAH1 in

Abstract:

Protein ubiquitination is one classic type of post-translational modification. The ubiquitin ligase E3 could interact directly with the substrate and mediate in large part the ubiquitination specificity. Arabidopsis thaliana BAH1 encodes a ubiquitin E3 ligase with a C3HC4-RING finger domain, which could bind two zinc ions to form a cross brace zinc finger. Here, we found the zinc finger structure of BAH1 and DnaJ was similar. Further self-ubiquitination assay in vitro demonstrated BAH1 possessed E3 ligase activity. We also found BAH1 can confer heat tolerance of E. coli as DnaJ by temperature-sensitive assays. Hence, these results indicated that BAH1 may improve heat tolerance of E. coli through interacting with DnaK/DnaJ chaperone system.

Key words:zinc finger; BAH1; DnaJ; ubiquitin E3 ligase