Cloning and characterization of a gene (mspA) encoding the major sheath protein of Treponema maltophilum ATCC 51939(T).

The major sheath protein-encoding gene (mspA) of the oral spirochete Treponema maltophilum ATCC 51939(T) was cloned by screening a genomic library with an anti-outer membrane fraction antibody. The mspA gene encodes a precursor protein of 575 amino acids with a predicted molecular mass of 62.3 kDa, including a signal peptide of 19 amino acids. The native MspA formed a heat-modifiable, detergent- and trypsin-stable complex which is associated with the outer membrane. Hybridization with an mspA-specific probe showed no cross-reactivity with the msp gene from Treponema denticola.