title: BpaB, a novel protein encoded by the Lyme disease spirochete's cp32 prophages, binds to erp Operator 2 DNA.
abstract: Borrelia burgdorferi produces Erp outer surface proteins throughout mammalian infection, but represses their synthesis during colonization of vector ticks. A DNA region 5' of the start of erp transcription, Operator 2, was previously shown to be essential for regulation of expression. We now report identification and characterization of a novel erp Operator 2-binding protein, which we named BpaB. erp operons are located on episomal cp32 prophages, and a single bacterium may contain as many as 10 different cp32s. Each cp32 family member encodes a unique BpaB protein, yet the three tested cp32-encoded BpaB alleles all bound to the same DNA sequence. A 20-bp region of erp Operator 2 was determined to be essential for BpaB binding, and initial protein binding to that site was required for binding of additional BpaB molecules. A 36-residue region near the BpaB carboxy terminus was found to be essential for high-affinity DNA-binding. BpaB competed for binding to erp Operator 2 with a second B. burgdorferi DNA-binding protein, EbfC. Thus, cellular levels of free BpaB and EbfC could potentially control erp transcription levels.
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536, USA.
authors.forename: Logan H
authors.initials: LH
authors.lastname: Burns
authors.forename: Claire A
authors.initials: CA
authors.lastname: Adams
authors.forename: Sean P
authors.initials: SP
authors.lastname: Riley
authors.forename: Brandon L
authors.initials: BL
authors.lastname: Jutras
authors.forename: Amy
authors.initials: A
authors.lastname: Bowman
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Chenail
authors.forename: Anne E
authors.initials: AE
authors.lastname: Cooley
authors.forename: Laura A
authors.initials: LA
authors.lastname: Haselhorst
authors.forename: Alisha M
authors.initials: AM
authors.lastname: Moore
authors.forename: Kelly
authors.initials: K
authors.lastname: Babb
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fried
authors.forename: Brian
authors.initials: B
authors.lastname: Stevenson
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D025065:Borrelia burgdorferi / Q000235:genetics* / Q000821:virology; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009875:Operator Regions, Genetic; D039002:Prophages / Q000235:genetics; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins