biostudies-literatureTandrup TDanish Council for Independent ResearchBioStruct-XDanish Ministry of Higher Education and ScienceNovo Nordisk Foundation HOPE projectNNF Center for BiosustainabilityNovo Nordisk FondenSeventh Framework Programme of the European Community666-681https://www.ebi.ac.uk/biostudies/studies/S-EPMC9438499biostudies-literatureUnknown9(Pt 5)The recently discovered lytic polysaccharide monooxygenases (LPMOs) are Cu-containing enzymes capable of degrading polysaccharide substrates oxidatively. The generally accepted first step in the LPMO reaction is the reduction of the active-site metal ion from Cu²⁺ to Cu⁺. Here we have used a systematic diffraction data collection method to monitor structural changes in two AA9 LPMOs, one from <i>Lentinus similis</i> (<i>Ls</i>AA9_A) and one from <i>Thermoascus auranti-acus</i> (<i>Ta</i>AA9_A), as the active-site Cu is photoreduced in the X-ray beam. For <i>Ls</i>AA9_A, the protein produced in two different recombinant systems was crystallized to probe the effect of post-translational modifications and different crystallization conditions on the active site and metal IUCrJChanges in active-site geometry on X-ray photoreduction of a lytic polysaccharide monooxygenase active-site copper and saccharide binding.PMC9438499Biofoundry and Strain Design TeamsNNF17SA0027704FP7/2007–2013NNF10CC10165178021-00273B283570Banerjee SLo Leggio LHernandez-Rollan CJohansen KSMeilleur FTandrup TMuderspach SJSantoni GIpsen JONorholm MHHfalseChanges in active-site geometry on X-ray photoreduction of a lytic polysaccharide monooxygenase active-site copper and saccharide binding.The recently discovered lytic polysaccharide monooxygenases (LPMOs) are Cu-containing enzymes capable of degrading polysaccharide substrates oxidatively. The generally accepted first step in the LPMO reaction is the reduction of the active-site metal ion from Cu²⁺ to Cu⁺. Here we have used a systematic diffraction data collection method to monitor structural changes in two AA9 LPMOs, one from <i>Lentinus similis</i> (<i>Ls</i>AA9_A) and one from <i>Thermoascus auranti-acus</i> (<i>Ta</i>AA9_A), as the active-site Cu is photoreduced in the X-ray beam. For <i>Ls</i>AA9_A, the protein produced in two different recombinant systems was crystallized to probe the effect of post-translational modifications and different crystallization conditions on the active site and metal 2022-01-01T00:00:00Z2022 Sep2026-05-28T06:47:20.936Z2025-02-19T03:29:00.643ZS-EPMC94384993607179510.1107/S2052252522007175