The EF0377 gene of Enterococcus faecalis was cloned and overexpressed in Escherichia coli. The protein has been purified and crystallized in three forms. Type III crystals belong to space group P2(1), with unit-cell parameters a = 72.11, b = 94.97, c = 80.77 A, beta = 111.93 degrees. There are four molecules per asymmetric unit and diffraction is observed to beyond 1.65 A under cryoconditions (100 K) using synchrotron radiation. An almost complete set of X-ray diffraction data was collected to 1.9 A from the native crystal.