InterPro domain: IPR044301

The pathogenesis-related protein-4 (PR-4) family is a group of proteins containing a BARWIN-like domain. This entry includes BARWIN from barley, PR4A/B from wheat, and AtHEL from Arabidopsis. In barley BARWIN is induced by wounding or pathogens [ 1 ]. Homologues of the BARWIN protein are also involved in the plant response to fungal infection and mechanical wounding [ 2 , 3 ]. Even though PR-4 proteins have been classified as chitinases, however, several BARWIN homologues have been shown to possess ribonuclease activity [ 4 , 4 ]. Antifungal DNase activity has also been observed, together with RNase activity, for the Theobroma cacao TcPR-4b protein [ 5 ].

1. Antifungal activity of chitin-binding PR-4 type proteins from barley grain and stressed leaf. FEBS Lett 307, 389-92
2. Structural and Functional Characterization of PR-4 SUGARWINs From Sugarcaneand Their Role in Plant Defense. Front Plant Sci 9, 1916
3. Structural basis of the antifungal activity of wheat PR4 proteins. FEBS Lett 583, 2865-71
4. Wheat pathogenesis-related proteins of class 4 have ribonuclease activity. FEBS Lett 575, 71-6
5. The pathogenesis-related protein PR-4b from Theobroma cacao presents RNase activity, Ca(2+) and Mg(2+) dependent-DNase activity and antifungal action on Moniliophthora perniciosa. BMC Plant Biol 14, 161