Article Figures & Data
Figures
- FIG. 1.
Charge distribution and hydropathy profile of the ZntB sequence. (A.) Regions of positive and negative charges were calculated by summing pK values of amino acids within a 15-residue sliding window. Regions with positive charge density are shaded grey, while regions with negative charge are shaded black. (B.) Hydropathy was determined by the algorithm of Kyte and Doolittle using a sliding window of 15 amino acids. Regions predicted to form transmembrane (TM) structures are denoted by open boxes.
- FIG. 2.
Model of the membrane topology of ZntB. Individual amino acids are depicted in single-letter code. Positively charged residues are enclosed in grey circles; negatively charged residues are enclosed in black circles. Locations of BlaM and LacZ fusions are labeled. The text following each fusion indicates the phenotype of the strain containing the plasmid encoding the chimera.
Tables
- TABLE 1.
Characteristics of ZntB chimeric proteins
Fusion plasmid Target residue Reporter Junction sequence β-Lactamase activitya β-Galactosidase activityb Cellular dispositionc ZntB Spacer Reporter pJH122 Met-217 LacZ HRRR LEVP SSNS 324 pAC27 Asp-219 LacZ RMQD VD GPNS 477 pAC31 Asp-219 BlaM RMQD VD HPET 20 Cyt pAC28 Arg-266 LacZ LARR VD GPNS 498 pAC32 Arg-266 BlaM LARR VD HPET 20 Cyt pAC29 Pro-295 LacZ GGIP VD GPNS 33 pAC33 Pro295 BlaM GGIP VD HPET 450 Mem pJH126 Gly-298 LacZ PGGG LEVP SSNS 00 pJH127 Gly-298 BlaM PGGG LEVP HPET 450 Mem pAC34 Arg-323 BlaM WLHR VD HPET 20 Mem pAC39 Leu327 LacZ SKWL VD GPNS 230 pAC45 Leu327 BlaM SKWL VD HPET 20 Mem ↵ a β-Lactamase activity is expressed as the MIC of ampicillin (in micrograms per milliliter).
↵ b β-Galactosidase specific activity is expressed in Miller units.
↵ c Cellular disposition was determined by Western blot analysis of cellular fractions with anti-BlaM antibody. Mem, fusion proteins that localized to the membrane; Cyt, fusion proteins that remained soluble in the cytoplasmic fraction.
