Md. Yoder et F. Jurnak, THE REFINED 3-DIMENSIONAL STRUCTURE OF PECTATE LYASE-C FROM ERWINIA-CHRYSANTHEMI AT 2.2-ANGSTROM RESOLUTION - IMPLICATIONS FOR AN ENZYMATICMECHANISM, Plant physiology, 107(2), 1995, pp. 349-364
The crystal structure of pectate lyase C (EC 4.2.2.2) from the enterob
acterium Erwinia chrysanthemi (PelC) has been refined by molecular dyn
amics techniques to a resolution of 2.2 Angstrom to an R factor of 17.
97%. The final model consists of 352 of the total 353 amino acids and
114 solvent molecules. The root-mean-square deviation from ideality is
0.009 Angstrom for bond lengths and 1.768 degrees for bond angles. Th
e structure of PelC bound to the lanthanide ion lutetium, used as a ca
lcium analog, has also been refined. Lutetium inhibits the enzymatic a
ctivity of the protein, and in the PelC-lutetium structure, the ion bi
nds in the putative calcium-binding site. Five side-chain atoms form l
igands to the lutetium ion. An analysis of the atomic-level model of t
he two protein structures reveals possible implications for the enzyma
tic mechanism of the enzyme.