2AE0

Crystal structure of MltA from Escherichia coli reveals a unique lytic transglycosylase fold

Summary for 2AE0

• Entry DOI: 10.2210/pdb2ae0/pdb
• Descriptor: Membrane-bound lytic murein transglycosylase A, 1,2-ETHANEDIOL, ACETIC ACID, ... (4 entities in total)
• Functional Keywords: double-psi beta-barrel, small mixed parallel/antiparallel six stranded beta barrel, helical sub-domain, hydrolase
• Biological source: Escherichia coli
• Cellular location: Cell outer membrane; Lipid-anchor: P0A935
• Total number of polymer chains: 1
• Total formula weight: 38372.81

Authors

Van Straaten, K.E.,Dijkstra, B.W.,Vollmer, W.,Thunnissen, A.M.W.H. (deposition date: 2005-07-21, release date: 2005-10-04, Last modification date: 2024-03-13)

Primary citation

van Straaten, K.E.,Dijkstra, B.W.,Vollmer, W.,Thunnissen, A.M.W.H.
Crystal Structure of MltA from Escherichia coli Reveals a Unique Lytic Transglycosylase Fold
J.Mol.Biol., 352:1068-1080, 2005

PubMed Abstract: Lytic transglycosylases are bacterial enzymes involved in the maintenance and growth of the bacterial cell-wall peptidoglycan. They cleave the beta-(1,4)-glycosidic bonds in peptidoglycan forming non-reducing 1,6-anhydromuropeptides. The crystal structure of the lytic transglycosylase MltA from Escherichia coli without a membrane anchor was solved at 2.0A resolution. The enzyme has a fold completely different from those of the other known lytic transglycosylases. It contains two domains, the largest of which has a double-psi beta-barrel fold, similar to that of endoglucanase V from Humicola insolens. The smaller domain also has a beta-barrel fold topology, which is weakly related to that of the RNA-binding domain of ribosomal proteins L25 and TL5. A large groove separates the two domains, which can accommodate a glycan strand, as shown by molecular modelling. Several conserved residues, one of which is in a position equivalent to that of the catalytic acid of the H.insolens endoglucanase, flank this putative substrate-binding groove. Mutation of this residue, Asp308, abolished all activity of the enzyme, supporting the direct participation of this residue in catalysis.

PubMed: 16139297
DOI: 10.1016/j.jmb.2005.07.067

Experimental method

X-RAY DIFFRACTION (2 Å)