RESUMO
The yeast Candida rugosa produces several closely related lipases which show a high degree of sequence identity (between 77 and 88% for pairs of proteins). Despite this high sequence identity, they exhibit markedly different substrate specificities, indicating that subtle structural differences may produce significant functional changes. Isoform 2 (lip2) has been crystallized using the hanging-drop vapour-diffusion method at 291 K. Diffraction-quality crystals have been obtained from two different experimental conditions (designated A and B, respectively). Type A crystals belong to space group P1 and have unit-cell parameters a = 62.15, b = 91.14, c = 108.46 A, alpha = 90.78, beta = 106.31, gamma = 86.91 degrees; type B crystals are monoclinic with a nearly hexagonal topology, with unit-cell parameters a = 116.11, b = 225.55, c = 116.06 A, beta = 119.89 degrees, and belong to space group P2(1). Diffraction data were collected to a resolution of 1.97 A at a synchrotron facility from type A crystals and to 2.65 A on an in-house rotating-anode generator from type B crystals. Whereas the triclinic crystal reveals monomeric lip2, the monoclinic crystal contains dimeric lip2.
