caa a22 4500 605499780 CHVBK 20210128100552.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00253-015-6534-0 doi (NATIONALLICENCE)springer-10.1007/s00253-015-6534-0 Bacterial expansins and related proteins from the world of microbes [Elektronische Daten] [Nikolaos Georgelis, Nikolas Nikolaidis, Daniel Cosgrove] The discovery of microbial expansins emerged from studies of the mechanism of plant cell growth and the molecular basis of plant cell wall extensibility. Expansins are wall-loosening proteins that are universal in the plant kingdom and are also found in a small set of phylogenetically diverse bacteria, fungi, and other organisms, most of which colonize plant surfaces. They loosen plant cell walls without detectable lytic activity. Bacterial expansins have attracted considerable attention recently for their potential use in cellulosic biomass conversion for biofuel production, as a means to disaggregate cellulosic structures by nonlytic means ("amorphogenesis”). Evolutionary analysis indicates that microbial expansins originated by multiple horizontal gene transfers from plants. Crystallographic analysis of BsEXLX1, the expansin from Bacillus subtilis, shows that microbial expansins consist of two tightly packed domains: the N-terminal domain D1 has a double-ψβ-barrel fold similar to glycosyl hydrolase family-45 enzymes but lacks catalytic residues usually required for hydrolysis; the C-terminal domain D2 has a unique β-sandwich fold with three co-linear aromatic residues that bind β-1,4-glucans by hydrophobic interactions. Genetic deletion of expansin in Bacillus and Clavibacter cripples their ability to colonize plant tissues. We assess reports that expansin addition enhances cellulose breakdown by cellulase and compare expansins with distantly related proteins named swollenin, cerato-platanin, and loosenin. We end in a speculative vein about the biological roles of microbial expansins and their potential applications. Advances in this field will be aided by a deeper understanding of how these proteins modify cellulosic structures. Springer-Verlag Berlin Heidelberg (outside the USA), 2015 Amorphogenesis nationallicence Biofuels nationallicence Cellulase synergism nationallicence Expansin nationallicence Plant-microbe interactions nationallicence Swollenin nationallicence Georgelis Nikolaos Simplot Plant Sciences, J.R. Simplot Company, 83706, Boise, ID, USA aut Nikolaidis Nikolas Department of Biological Science, California State University, 92831, Fullerton, CA, USA aut Cosgrove Daniel Department of Biology, Penn State University, 16802, University Park, PA, USA aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/9(2015-05-01), 3807-3823 0175-7598 99:9<3807 2015 99 253 https://doi.org/10.1007/s00253-015-6534-0 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 review-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6534-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Georgelis Nikolaos Simplot Plant Sciences, J.R. Simplot Company, 83706, Boise, ID, USA aut NATIONALLICENCE 700 1- Nikolaidis Nikolas Department of Biological Science, California State University, 92831, Fullerton, CA, USA aut NATIONALLICENCE 700 1- Cosgrove Daniel Department of Biology, Penn State University, 16802, University Park, PA, USA aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/9(2015-05-01), 3807-3823 0175-7598 99:9<3807 2015 99 253