SmpB: a novel outer membrane protein present in some Brachyspira hyodysenteriae strains.
A novel outer membrane protein-encoding gene was identified in Brachyspira hyodysenteriae. The predicted protein, SmpB, was encoded by a gene that contains regions of identity with that encoding the previously identified lipoprotein SmpA. However, the majority of the reading frame encoding SmpA and SmpB share no detectable similarity. Analysis of several strains revealed that B. hyodysenteriae harbours either smpA or the newly identified gene smpB, but not both. smpB encodes for a slightly larger protein than smpA, 17.6 and 16.8 kDa, respectively. The predicted proteins share an identical leader sequence and the first 10 amino acids of the mature protein, however, the remainder of the predicted protein sequence shows no similarity. It is hypothesised that smpA and smpB are present on the same area of the chromosome. The proteins are antigenically unique, as antisera raised against a strain of B. hyodysenteriae that expresses SmpA cannot detect SmpB and vice versa. Although the presence of an identical leader peptide suggests identical localisation of SmpA and SmpB, it is not known if the two predicted proteins share similar function.
Holden
James
J
School of Applied Sciences, PO Box 71, RMIT University, Bundoora 3083, Australia.
Moutafis
George
G
Istivan
Taghrid
T
Coloe
Peter J
PJ
Smooker
Peter M
PM
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D015139:Blotting, Southern / Q000379:methods; D017401:Brachyspira hyodysenteriae / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D000939:Epitopes; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D015151:Immunoblotting / Q000379:methods; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000276:immunology / Q000502:physiology; D011817:Rabbits; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013145:Spirochaetales Infections / Q000382:microbiology / Q000662:veterinary; D013552:Swine
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D000939:Epitopes; D016601:RNA-Binding Proteins; C430328:small protein B