title: Crystallization and preliminary X-ray analysis of carnein, a serine protease from Ipomoea carnea.
abstract: Carnein is an 80 kDa subtilisin-like serine protease from the latex of the plant Ipomoea carnea which displays an exceptional resistance to chemical and thermal denaturation. In order to obtain the first crystal structure of a plant subtilisin and to gain insight into the structural determinants underlying its remarkable stability, carnein was isolated from I. carnea latex, purified and crystallized by the hanging-drop vapour-diffusion method. A data set was collected to 2.0 A resolution in-house from a single crystal at 110 K. The crystals belonged to the trigonal space group P3(1)21 or P3(2)21, with unit-cell parameters a = b = 126.9, c = 84.6 A, alpha = beta = 90, gamma = 120 degrees. Assuming the presence of one molecule per asymmetric unit, the Matthews coefficient is 2.46 A(3) Da(-1), corresponding to a solvent content of 50%. Structure determination of the enzyme is in progress.
authors.affiliation: Molecular Biology Unit, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India.
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Patel
authors.forename: Niels
authors.initials: N
authors.lastname: van Oosterwijk
authors.forename: Vijay Kumar
authors.initials: VK
authors.lastname: Singh
authors.forename: Henriëtte J
authors.initials: HJ
authors.lastname: Rozeboom
authors.forename: Kor H
authors.initials: KH
authors.lastname: Kalk
authors.forename: Roland J
authors.initials: RJ
authors.lastname: Siezen
authors.forename: Medicherla V
authors.initials: MV
authors.lastname: Jagannadham
authors.forename: Bauke W
authors.initials: BW
authors.lastname: Dijkstra