The endo-1,5-α- l-arabinanases belonging to glycoside hydrolase family 43 are of great industrial interest for use in food technology, organic synthesis and biofuel production owing to their ability to catalyze the hydrolysis of α-1,5-arabinofuranosidic bonds in arabinose-containing polysaccharides. In this work, Thermotoga petrophila endo-1,5-α- l-arabinanase, a GH43-family member, has been cloned, overexpressed, purified and crystallized. Single crystals were obtained from a solution containing 0.1 M MES buffer pH 6.5, 0.8 M ammonium sulfate, 0.1 M EDTA, 0.1 M l-proline and 5%( v/ v) dioxane. X-ray diffraction data were collected to a resolution of 2.86 Å using synchrotron radiation and the diffraction pattern was indexed in the tetragonal space group P422, with unit-cell parameters a = b = 83.71, c = 408.25 Å. [ABSTRACT FROM AUTHOR]