0.36 nm per amino acid (71). Contour lengths and rupture forces have been analyzed statistically, and contour-length histograms were produced. Peaks in these histograms have been simultaneously fitted making use of a sum of Gaussian distributions (46). This procedure revealed the imply contour lengths on the unfolded and stretched polypeptides of DtpA and indicated the border positions from the steady structural segments that have been mapped on the secondary structure of DtpA. Membrane compensation was applied for borders that occurred on the support-facing side in the membrane or inside the membrane plane (49, 50). Force histograms had been compiled for each force peak determined from contour-length histograms. On top of that, the probability of occurrence was calculated for every force peak. Information visualization, statistical evaluation, and calculations have been performed making use of custom and built-in procedures for IgorPro six (Wavemetrics). ACKNOWLEDGMENTS. We thank J. Tittel for support with data acquisition. This function was supported by the Deutsche Forschungsgemeinschaft, Grant 09-EuroSYNBIO-FP-012 NANOCELL from the European Science Foundation, the Swiss National Science Foundation, the University of Bern, as well as the National Centre of Competence in Research TransCure.1016241-80-7 web Bippes et al.Formula of 181934-30-5 PNAS | Published on line September 30, 2013 | EBIOCHEMISTRYPNAS PLUS1. Steiner H-Y, Naider F, Becker JM (1995) The PTR family: A brand new group of peptide transporters.PMID:33666885 Mol Microbiol 16(5):825?34. two. Daniel H, Spanier B, Kottra G, Weitz D (2006) From bacteria to man: Archaic protondependent peptide transporters at perform. Physiology (Bethesda) 21(2):93?02. three. Tougher D, et al. (2008) DtpB (YhiP) and DtpA (TppB, YdgR) are prototypical protondependent peptide transporters of Escherichia coli. FEBS J 275(13):3290?298. 4. Weitz D, et al. (2007) Functional and structural characterization of a prokaryotic peptide transporter with attributes related to mammalian PEPT1. J Biol Chem 282(5): 2832?839. 5. Hagting A, Kunji ERS, Leenhouts KJ, Poolman B, Konings WN (1994) The di- and tripeptide transport protein of Lactococcus lactis. A brand new variety of bacterial peptide transporter. J Biol Chem 269(15):11391?1399. six. Nakajima H, Hagting A, Kunji ERS, Poolman B, Konings WN (1997) Cloning and functional expression in Escherichia coli of your gene encoding the di- and tripeptide transport protein of Lactobacillus helveticus. Appl Environ Microbiol 63(six):2213?217. 7. Perry JR, Basrai MA, Steiner HY, Naider F, Becker JM (1994) Isolation and characterization of a Saccharomyces cerevisiae peptide transport gene. Mol Cell Biol 14(1): 104?15. eight. Biegel A, et al. (2006) The renal variety H+/peptide symporter PEPT2: Structure-affinity relationships. Amino Acids 31(two):137?56. 9. Daniel H, Kottra G (2004) The proton oligopeptide cotransporter family SLC15 in physiology and pharmacology. Pflugers Arch 447(5):610?18. 10. Newstead S, et al. (2011) Crystal structure of a prokaryotic homologue on the mammalian oligopeptide-proton symporters, PepT1 and PepT2. EMBO J 30(2):417?26. 11. Ernst HA, et al. (2009) Ligand binding analyses from the putative peptide transporter YjdL from E. coli display a considerable selectivity towards dipeptides. Biochem Biophys Res Commun 389(1):112?16. 12. Meredith D (2009) The mammalian proton-coupled peptide cotransporter PepT1: Sitting around the transporter-channel fence? Philos Trans R Soc Lond B Biol Sci 364(1514): 203?07. 13. Rubio-Aliaga I, Daniel H (2002) Mammalian peptide transporters as targets for drug delivery. Trends Ph.