SPX domain of the E3 ubiquitin-protein ligase BAH1/NLA and similar proteins.
This region has been named the SPX domain after (Syg1, Pho81 and XPR1). The domain is found at the amino terminus of a variety of proteins. BAH1 (benzoic acid hypersensitive 1) appears to function as an E3 ubiquitin ligase; the protein contains an SPX and a RING finger domain. It has been suggested that BAH1/NLA is involved in the regulation of plant immune responses, probably via a pathway of salicylic acid biosynthesis that includes benzoic acid as an intermediate.