title: Characterization of the Moraxella catarrhalis uspA1 and uspA2 genes and their encoded products.
abstract: The uspA1 and uspA2 genes of M. catarrhalis O35E encode two different surface-exposed proteins which were previously shown to share a 140-amino-acid region with 93% identity (C. Aebi, I. Maciver, J. L. Latimer, L. D. Cope, M. K. Stevens, S. E. Thomas, G. H. McCracken, Jr., and E. J. Hansen, Infect. Immun. 65:4367-4377, 1997). The N-terminal amino acid sequences of the mature forms of both UspA1 and UspA2 from strain O35E were determined after enzymatic treatment to remove the N-terminal pyroglutamyl residue that had blocked Edman degradation. Mass spectrometric analysis indicated that the molecular mass of UspA1 from M. catarrhalis O35E was 83,500 +/- 116 Da. Nucleotide sequence analysis of the uspA1 and uspA2 genes from three other M. catarrhalis strains (TTA24, ATCC 25238, and V1171) revealed that the encoded protein products were very similar to those from strain O35E. Western blot analysis was used to confirm that each of these three strains of M. catarrhalis expressed both UspA1 and UspA2 proteins. Several different and repetitive amino acid motifs were present in both UspA1 and UspA2 from these four strains, and some of these were predicted to form coiled coils. Linear DNA templates were used in an in vitro transcription-translation system to determine the sizes of the monomeric forms of the UspA1 and UspA2 proteins from strains O35E and TTA24.
authors.affiliation: Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas 75235-9048, USA.
authors.forename: L D
authors.initials: LD
authors.lastname: Cope
authors.forename: E R
authors.initials: ER
authors.lastname: Lafontaine
authors.forename: C A
authors.initials: CA
authors.lastname: Slaughter
authors.forename: C A
authors.initials: CA
authors.lastname: Hasemann
authors.forename: C
authors.initials: C
authors.lastname: Aebi
authors.forename: F W
authors.initials: FW
authors.lastname: Henderson
authors.forename: G H
authors.initials: GH
authors.lastname: McCracken
authors.forename: E J
authors.initials: EJ
authors.lastname: Hansen
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics*; D000954:Antigens, Surface / Q000096:biosynthesis / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D015870:Gene Expression; D005798:Genes, Bacterial; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D001936:Moraxella catarrhalis / Q000235:genetics*; D014176:Protein Biosynthesis; D020449:Repetitive Sequences, Amino Acid; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014158:Transcription, Genetic
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; C089675:UspA protein, Moraxella catarrhalis