Open AccessCutting at the right place
Author(s) -
GomisRüth F. Xavier,
GómezOrtiz Mariola,
Vendrell Josep,
Ventura Salvador,
Bode Wolfram,
Huber Robert,
Avilés Francesc X.
Publication year - 1998
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1998.2510839.x
Subject(s) - chymotrypsinogen , carboxypeptidase , subtilisin , subfamily , zymogen , pancreatic elastase , protein subunit , serine , ternary complex , chemistry , chymotrypsin , biochemistry , stereochemistry , enzyme , crystallography , elastase , trypsin , gene
Proteinase E is a proteolytic enzyme which belongs to a distinct subfamily of chymotrypsin‐like serine endopeptidases. Its proform from the bovine pancreatic system has been structurally analyzed by X‐ray crystallography for the intact native form, with a 11‐residue N‐terminal activation peptide, in a ternary complex with chymotrypsinogen C and procarboxypeptidase A [Gomis‐Rüth, F. X., Gómez, M., Bode, W., Huber, R. & Avilés, F. X. (1995) The three‐dimensional structure of the native ternary complex of bovine pancreatic procarboxypeptidase A with proproteinase E and chymotrypsinogen C, EMBO J. 14 , 4387−4394]. Also for a N‐terminally truncated form, lacking the first 13 residues and called subunit III, a crystal structure is available [Pignol, D., Gaboriaud, C., Michon, T., Kerfelec, B., Chapus, C. & Fontecilla‐Camps, J. C. (1994) Crystal structure of bovine procarboxypeptidase A‐S6 subunit III, a highly structured truncated zymogen E, EMBO J. 8 , 1763−1771]. Both structures are well defined by electron density, except for the first 7 residues of subunit III. However, both structures present large deviations of up to 2 nm in several regions, indicating that they correspond to two quite distinct states of low free energy, influenced by very few contacts made via the N‐terminal segment. As no structure of an active proteinase E is known so far, pancreatic porcine elastase has been chosen as a model for this enzyme and an activation mechanism for this distinct serine endopeptidase subfamily is proposed.