Se. Lietzke et al., THE REFINED 3-DIMENSIONAL STRUCTURE OF PECTATE LYASE-E FROM ERWINIA-CHRYSANTHEMI AT 2.2-ANGSTROM RESOLUTION, Plant physiology, 111(1), 1996, pp. 73-92
The crystal structure of pectate lyase E (Pelf; EC 4.2.2.2) from the e
nterobacteria Erwinia chrysanthemi has been refined by molecular dynam
ics techniques to a resolution of 2.2 Angstrom and an R factor (an agr
eement factor between observed structure factor amplitudes) of 16.1%.
The final model consists of all 355 amino acids and 157 water molecule
s. The root-mean-square deviation from ideality is 0.009 Angstrom for
bond lengths and 1.721 degrees for bond angles. The structure of Pelf
bound to a lanthanum ion, which inhibits the enzymatic activity, has a
lso been refined and compared to the metal-free protein. In addition,
the structures of pectate lyase C (PelC) in the presence and absence o
f a lutetium ion have been refined further using an improved algorithm
for identifying waters and other solvent molecules. The two putative
active site regions of Pelf have been compared to those in the refined
structure of PelC. The analysis of the atomic details of Pelf and Pel
C in the presence and absence of lanthanide ions provides insight into
the enzymatic mechanism of pectate lyases.