http://www.diva-portal.org Postprint This is the accepted version of a paper published in Plant Molecular Biology. This paper has been peer- reviewed but does not include the final publisher proof-corrections or journal pagination. Citation for the original published paper (version of record): Ubhayasekera, W., Rawat, R., Ho, S., Wiweger, M., von Arnold, S. et al. (2009) The first crystal structures of a family 19 class IV chitinase: the enzyme from Norway spruce. Plant Molecular Biology, 71(3): 277-289 http://dx.doi.org/10.1007/s11103-009-9523-9 Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. Permanent link to this version: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-142125