2ZXQ:
reference: Crystallographic and mutational analyses of substrate recognition of endo-{alpha}-N-acetylgalactosaminidase from Bifidobacterium longum., Suzuki R, Katayama T, Kitaoka M, Kumagai H, Wakagi T, Shoun H, Ashida H, Yamamoto K, Fushinobu S, J Biochem. 2009 Jun 8. PMID: 19502354

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