We describe the cloning, overexpression, purification, characterization and crystal structure of chitinase G, a single-domain family 19 chitinase from the Gram-positive bacterium Streptomyces coelicolorA3(2). Although chi-tinase G was not capable of releasing 4-methylumbelliferyl from artificial chitooligosaccharide substrates, it was capable of degrading longer chito-oligosaccharides at rates similar to those observed for other chitinases.