title: Identification of ligand specificity determinants in lantibiotic bovicin HJ50 and the receptor BovK, a multitransmembrane histidine kinase.
abstract: Lantibiotic bovicin HJ50 is produced by Streptococcus bovis HJ50 and acts as the extracellular signal to autoregulate its own biosynthesis through BovK/R two-component system. Bovicin HJ50 shows a linear N-terminal and glubolar C-terminal structure, and the sensor histidine kinase BovK contains eight transmembrane segments lacking any extensive surface-exposed sensory domain. The signal recognition mechanism between bovicin HJ50 and BovK is still unknown. We performed saturated alanine scanning mutagenesis and other amino acid substitutions on bovicin HJ50 using a semi-in vitro biosynthesis. Results of the mutants inducing activities indicated that several charged and hydrophobic amino acids in ring B of bovicin HJ50, as well as two glycines were key residues to recognize BovK. Circular dichroism analyses indicated that both glycines contributed to bovicin HJ50 structural changes in the membrane. Biotin-labeled bovicin HJ50 could interact with the N-terminal sensor of BovK, and several charged residues and a conserved hydrophobic region in the N-terminal portion of BovK sensor domain were important for interacting with the signal bovicin HJ50. By combining the results, we suggested a mechanism of bovicin HJ50 recognizing and activating BovK mainly through electrostatic and hydrophobic interactions.
authors: From the State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences and.
authors: Kunling
authors: K
authors: Teng
authors: Jie
authors: J
authors: Zhang
authors: Xue
authors: X
authors: Zhang
authors: Xiaoxuan
authors: X
authors: Ge
authors: Yong
authors: Y
authors: Gao
authors: Jian
authors: J
authors: Wang
authors: Yuheng
authors: Y
authors: Lin
authors: Jin
authors: J
authors: Zhong
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000071677:Histidine Kinase; D009154:Mutation; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000502:physiology*; D016985:Streptococcus bovis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D011494:Protein Kinases; D000071677:Histidine Kinase
keywords: Antimicrobial Peptides; BovK; Bovicin HJ50; Histidine Kinases; Lantibiotics; Membrane Proteins; Protein-Protein Interactions; Signal Transduction