1 A cellulase that binds helical and planar conformations of cellulose and displays structural conservation with lytic transglycosylases Running title: A GH119 cellulase Joana L.A. Brás *,1 , Alan Cartmell †,1 , Ana Luísa Carvalho # , Genny Verzé #‡ , Edward A. Bayer ¶ , Yael Vazana ¶ , Márcia A.S. Correia * , José A. M. Prates * , Supriya Ratnaparkhe † , Alisdair B. Boraston § , Maria João Romão # , Carlos M.G.A. Fontes *,2 and Harry J. Gilbert †,2 * CIISA – Faculdade de Medicina Veterinária, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal; † Complex Carbohydrate Research Centre, University of Georgia, Athens, Georgia 30602-4712, USA. # REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. ‡ Biocrystallography Laboratory, Department of Biotechnology, University of Verona, Verona, Italy. ¶ Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100 Israel. § Alaisdair Boraston§Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, Canada V8W 3P6 Major category: Biological Sciences Minor Categories: Biochemistry 1 Equal contribution 2 Corresponding authors. H. J. Gilbert; E-mail hgilbert@ccrc.uga.edu , Tel No. 706-583-0655, Fax No. 706-542-4412. A. L. Carvalho; E-mail: alcarvalho@dq.fct.unl.pt Data deposition: Coordinates and observed structure factor amplitudes for the CtCel119A - cellotriose(2) complex, to 1.5 Å resolution, have been deposited in the Protein Data Bank in Europe (PDBe), www.ebi.ac.uk/pdbe (PDB ID code 2wxa).