The lipase of Rhizomucor miehei was measured at two different wavelengths (synchroton lambda = 1.06 A and at a rotating anode lambda = 1.542 A) and two temperatures (293 and 110 K). The structure could be solved using the C alpha-coordinates from the Brookhaven data base (code name 1TGL). Both structures were refined to R-values of 18.7% (synchrotron 293 K) and 20.0% (rotating anode 110 K) at a resolution of 8-2.3 and 8-2.5 A, respectively. Both structures are almost identical to the original 1TGL data set. The side chain positions of both crystal structures differ mainly in the parts of the molecule with relatively high temperature factors in the crystallographic refinement. The low-temperature structure forms more hydrogen bridges than the room temperature structure. From the results of Brzozowski et al. (1991), a preliminary model of the active RML was constructed. A docking of trilaurylglycerol led to a first model of the complex of RML/substrate.