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Membrane insertion stabilizes the structure of TrwB, the R388 conjugative plasmid coupling protein

, : Membrane insertion stabilizes the structure of TrwB, the R388 conjugative plasmid coupling protein. Biochimica et Biophysica Acta 1808(4): 1032-1039

TrwB is an integral membrane protein that plays a crucial role in the conjugative process of plasmid R388. We have recently shown [Vecino et al., Biochim. Biophys. Acta 1798(11), 2160-2169 (2010)] that TrwB can be reconstituted into liposomes, and that bilayer incorporation increases its affinity for nucleotides and its specificity for ATP. In the present contribution we examine the structural effects of membrane insertion on TrwB, by comparing the protein in reconstituted form and in the form of protein/lipid/detergent mixed micelles. TrwB was reconstituted in PE:PG:CL (76.3:19.6:4.1mol ratio) with a final 99:1 lipid:protein mol ratio. This lipid mixture is intended to mimic the bacterial inner membrane composition, and allows a more efficient reconstitution than other lipid mixtures tested. The studies have been carried out mainly using infrared spectroscopy, because this technique provides simultaneously information on both the lipid and protein membrane components. Membrane reconstitution of TrwB is accompanied by a decrease in β-sheet contents and an increase in β-strand structures, probably related to protein-protein contacts in the bilayer. The predominant α-helical component remains unchanged. The bilayer-embedded protein becomes thermally more stable, and also more resistant to trypsin digestion. The properties of the bilayer lipids are also modified in the presence of TrwB, the phospholipid acyl chains are slightly ordered, and the phosphate groups at the interface become more accessible to water. In addition, we observe that the protein thermal denaturation affects the lipid thermal transition profile.


PMID: 21211515

DOI: 10.1016/j.bbamem.2010.12.025

Other references

Roth, M.; Krkoska, J.; Procházka, J.; Holub, V., 1978: Stenosis of cerebral vessels in children. Ceskoslovenska Radiologie 32(6): 380-383

Kross, E.K.; Engelberg, R.A.; Gries, C.J.; Nielsen, E.L.; Zatzick, D.; Curtis, J.Randall., 2011: ICU care associated with symptoms of depression and posttraumatic stress disorder among family members of patients who die in the ICU. Psychologic symptoms of posttraumatic stress disorder (PTSD) and depression are relatively common among family members of patients who die in the ICU. The patient-level risk factors for these family symptoms are not well understood but may help to...

Majack, R.A.; Bornstein, P., 1985: Regulation of collagen biosynthesis. Heparin alters the biosynthetic phenotype of vascular smooth muscle cells. Annals of the New York Academy of Sciences 460: 172-180

Burmeister, H., 1954: Lipoblastic sarcomatosis. Bruns' Beitrage Zur Klinischen Chirurgie 188(1): 35-58

Ueno, A., 1962: Pharmaceutical studies on ferns. XVII. Components of Athyrium mesosorum Makino. (2). Yakugaku Zasshi 82: 1486-1488

Gupta, D.; Asthana, B., 1985: Systems approach in conjunctive development of water resources. Formulation and appraisal of irrigation projects: proceedings of a national symposium March 28-30-1985: 5

Anonymous, 1979: Report by the Committee for Agriculture on the market outlook for cereals animal feed and livestock products and its wider economic implications October 1979. The outlook for the main agricultural products of OECD Member countries - cereals, proteins for animal feeds, meat and dairy products - together with the inter-relations between them, was assessed by the Committee for Agriculture at its meeting on...

Fearnley, C.; Manning, G.; Bagnall, M.; Javed, M.Afzal.; Wassenaar, T.M.; Newell, D.G., 2008: Identification of hyperinvasive Campylobacter jejuni strains isolated from poultry and human clinical sources. Campylobacter jejuni causes gastroenteritis with a variety of symptoms in humans. In the absence of a suitable animal model, in vitro models have been used to study virulence traits such as invasion and toxin production. In this study, 113 C. jeju...

Koretskaia, T.I.; Moskaleva, G.P.; Gudim, V.I.; Serebrianaia, B.A., 1969: A method for determining erythropoietin in polycythemic mice. Patologicheskaia Fiziologiia i Eksperimental'naia Terapiia 13(3): 77-79

Rausser, G.; Lapan, H., 1979: Natural resources, goods, bads and alternative institutional frameworks. The purpose of this paper is to extend and modify the neoclassical paradigm to adequately account for the unique features of natural resources. These unique features relate to the common property nature of resources, pollution and associated exter...