2pns
From Proteopedia
1.9 Angstrom resolution crystal structure of a plant cysteine protease Ervatamin-C refinement with cDNA derived amino acid sequence
Overview
We report here the cloning and characterization of the entire cDNA of a papain-like cysteine protease from a tropical flowering plant. The 1098-bp ORF of the cDNA codify a protease precursor having a signal peptide of 19 amino acids, a cathepsin-L like N-terminal proregion of 114 amino acids, a mature enzyme part of 208 amino acids and a C-terminal proregion of 24 amino acids. The derived amino acid sequence of the mature part tallies with the thermostable cysteine protease Ervatamin-C--as was aimed at. The C-terminal proregion of the protease has altogether a different sequence pattern not observed in other members of the family and it contains a negatively charged helical zone. The three-dimensional model of the precursor, based on the homology modeling and X-ray structure, shows that the extended peptide stretch region of the N-terminal propeptide, covering the interdomain cleft, contains protruding side chains of positively charged residues. This study also indicates that the negatively charged zone of C-terminal propeptide may interact with the positively charged zone of the N-terminal propeptide in a cooperative manner in the maturation process of this enzyme.
About this Structure
Full crystallographic information is available from OCA.
Reference
A thermostable cysteine protease precursor from a tropical plant contains an unusual C-terminal propeptide: cDNA cloning, sequence comparison and molecular modeling studies., Ghosh R, Dattagupta JK, Biswas S, Biochem Biophys Res Commun. 2007 Nov 3;362(4):965-70. Epub 2007 Aug 28. PMID:17767923 Page seeded by OCA on Sun May 4 13:29:55 2008
