P. Sliz et al., CRYSTALLIZATION AND PRELIMINARY STRUCTURAL STUDIES OF LACTOSE-SPECIFIC ENZYME IIA FROM LACTOCOCCUS-LACTIS, Acta crystallographica. Section D, Biological crystallography, 52, 1996, pp. 1199-1201
Crystallography,"Biochemical Research Methods",Biology
Lactose-specific enzyme IIA of the phosphoenol:pyruvate-dependent suga
r phosphotransferase system from Lactococcus lactis has been crystalli
zed in phosphate buffer. The crystals belong to space group P4(1)2(1)2
or its enantiomorph P4(3)2(1)2 with unit-cell axes a = b = 90.9 and c
= 82.4 Angstrom. The packing parameter (Matthews parameter) V-m of 2.
48 Angstrom(3) Da(-1) is consistent with one trimer per asymmetric uni
t and non-crystallographic threefold symmetry has been confirmed by ca
lculating a self-rotation function. The crystals diffract X-rays to at
least 2.3 Angstrom resolution, are stable in an X-ray beam and are th
erefore appropriate for structure determination. Native data to 2.3 An
gstrom resolution have been collected using a MAR image-plate system a
t a synchrotron source. One isomorphous heavy-atom derivative has been
identified and the presence of an isomorphous signal in the data has
been confirmed by Patterson methods.