High-resolution structure of the major periplasmic domain from the cell shape-determining filament MreC.
Bacterial cell shape is dictated by the cell wall, a plastic structure that must adapt to growth and division whilst retaining its function as a selectively permeable barrier. The modulation of cell wall structure is achieved by a variety of enzymatic functions, all of which must be spatially regulated in a precise manner. The membrane-spanning essential protein MreC has been identified as the central hub in this process, linking the bacterial cytoskeleton to a variety of cell wall-modifying enzymes. Additionally, MreC can form filaments, believed to run perpendicularly to the membrane. We present here the 1.2 A resolution crystal structure of the major periplasmic domain of Streptococcus pneumoniae MreC. The protein shows a novel arrangement of two barrel-shaped domains, one of which shows homology to a known protein oligomerization motif, with the other resembling a catalytic domain from a bacterial protease. We discuss the implications of these results for MreC function, and detail the structural features of the molecule that may be responsible for the binding of partner proteins.
Lovering
Andrew L
AL
Department of Biochemistry and Molecular Biology and Center for Blood Research, The University of British Columbia, Vancouver, Canada V6T 1R9.
Strynadka
Natalie C J
NCJ
Department of Biochemistry and Molecular Biology and Center for Blood Research, The University of British Columbia, Vancouver, Canada V6T 1R9. Electronic address: natalie@byron.biochem.ubc.ca.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D048430:Cell Shape; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013296:Streptococcus pneumoniae / Q000737:chemistry / Q000166:cytology
D001426:Bacterial Proteins; C062061:MreC protein, Bacteria