Hi Jane, the Whatif server lists the secondary structure according to DSSP. http://swift.cmbi.ru.nl/servers/html/index.html -> Protein analysis -> Secondary Structure, symmetry and accessibility Best regards, Daniel -- Daniel Schlieper email: [log in to unmask] Biochemie der Pflanzen phone: +49 211 8115232 Heinrich-Heine-Universitaet fax : +49 211 8113569 40225 Duesseldorf, Germany http://www.biologie.uni-duesseldorf.de