Classification of hyper-variable Corynebacterium glutamicum surface-layer proteins by sequence analyses and atomic force microscopy.
The structural S-layer proteins of 28 different Corynebacterium glutamicum isolates have been analyzed systematically. Treatment of whole C. glutamicum cells with detergents resulted in the isolation of S-layer proteins with different apparent molecular masses, ranging in size from 55 to 66 kDa. The S-layer genes analyzed were characterized by coding regions ranging from 1,473 to 1,533 nucleotides coding for S-layer proteins with a size of 490-510 amino acids. Using PCR techniques, the corresponding S-layer genes of the 28 C. glutamicum isolates were all cloned and sequenced. The deduced amino acid sequences of the S-layer proteins showed identities between 69 and 98% and could be grouped into five phylogenetic classes. Furthermore, sequence analyses indicated that the S-layer proteins of the analyzed C. glutamicum isolates exhibit a mosaic structure of highly conserved and highly variable regions. Several conserved regions were assumed to play a key role in the formation of the C. glutamicum S-layers. Especially the N-terminal signal peptides and the C-terminal anchor sequences of the S-layer proteins showed a nearly perfect amino acid sequence conservation. Analyses by atomic force microscopy revealed a committed hexagonal structure. Morphological diversity of the C. glutamicum S-layers was observed in a class-specific unit cell dimension (ranging from 15.2 to 17.4 nm), which correlates with the sequence similarity-based classification. It could be demonstrated that differences in the primary structure of the S-layer proteins were reflected by the S-layer morphology.
Lehrstuhl für Genetik, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
Nicole
N
Hansmeier
Frank W
FW
Bartels
Robert
R
Ros
Dario
D
Anselmetti
Andreas
A
Tauch
Alfred
A
Pühler
Jörn
J
Kalinowski
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000145:classification* / Q000648:ultrastructure; D048230:Corynebacterium glutamicum / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000145:classification* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force / Q000379:methods*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D016415:Sequence Alignment / Q000379:methods; D020539:Sequence Analysis, Protein / Q000379:methods*; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D008562:Membrane Glycoproteins; C055764:S-layer proteins