title: The Mycobacterium avium-intracellulare complex dnaB locus and protein intein splicing.
abstract: Intein is a protein sequence mebedded in-frame within a precursor protein and is posttranslationally excised by a self-catalytic protein splicing process. Protein splicing is believed to follow a pathway requiring Cys, Ser, or Thr residues at the intein N-terminus and substitutions other than Cys, Ser, or Thr residues prevent splicing. We show that the dnaB locus in some strains of M. avium-intracellulare complex (MAC) contains intein and that the intein N-terminal amino acid is Ala [Ala-type]. We demonstrate that the M. avium DnaB precursor protein undergoes posttranslational proteolytic processing producing proteins corresponding to the sizes of the DnaB and intein. Further, by Western analysis we detect a protein corresponding to the size of the spliced DnaB protein in MAC cell extracts. Together, these results indicate that the Ala-type MAC DnaB inteins can splice and provide another example that points to an interesting alternative splicing mechanism (Southworth, M. W., Benner, J., and Perler, F. B., EMBO J. 19, 5019-5026, 2000).
authors.affiliation: Biomedical Research, University of Texas Health Center at Tyler, 11937 US Highway at 271, Tyler, Texas 75708-3154, USA.
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: B
authors.initials: B
authors.lastname: Low
authors.forename: S A
authors.initials: SA
authors.lastname: Rutherford
authors.forename: M
authors.initials: M
authors.lastname: Rajagopalan
authors.forename: M V
authors.initials: MV
authors.lastname: Madiraju
mesh_terms: D001426:Bacterial Proteins; D001483:Base Sequence; D004265:DNA Helicases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D053488:DnaB Helicases; D005798:Genes, Bacterial; D015269:Mycobacterium avium Complex / Q000235:genetics* / Q000378:metabolism*; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019154:Protein Splicing; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D011498:Protein Precursors; D011994:Recombinant Proteins; D004265:DNA Helicases; D053488:DnaB Helicases