Cell wall of Thermoanaerobacterium thermosulfurigenes EM1: isolation of its components and attachment of the xylanase XynA.
Thermoanaerobacterium thermosulfurigenes EM1 has a gram-positive type cell wall completely covered by a surface layer (S-layer) with hexagonal lattice symmetry. The components of the cell envelope were isolated, and the S-layer protein was purified and characterized. S-layer monomers assembled in vitro into sheets with the same hexagonal symmetry as in vivo. Monosaccharide analysis revealed that the S-layer is associated with fucose, rhamnose, mannosamine, glucosamine, galactose, and glucose. The N-terminal 31 amino acid residues of the S-layer protein showed significant similarity to SLH (S-layer homology) domains found in S-layer proteins of different bacteria and in the exocellular enzymes pullulanase, polygalacturonate hydrolase, and xylanase of T. thermosulfurigenes EM1. The xylanase from T. thermosulfurigenes EM1 was copurified with the S-layer protein during isolation of cell wall components. Since SLH domains of some structural proteins have been shown to anchor these proteins noncovalently to the cell envelope, we propose a common anchoring mechanism for the S-layer protein and exocellular enzymes via their SLH domains in the peptidoglycan-containing layer of T. thermosulfurigenes EM1.
Brechtel
E
E
Abteilung Mikrobiologie, Universtität Rostock, Germany.
Matuschek
M
M
Hellberg
A
A
Egelseer
E M
EM
Schmid
R
R
Bahl
H
H
D000595:Amino Acid Sequence; D001421:Bacteria, Anaerobic / Q000737:chemistry* / Q000201:enzymology* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000302:isolation & purification / Q000378:metabolism*
D001426:Bacterial Proteins; D008565:Membrane Proteins; D009005:Monosaccharides; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase