porin-like complex
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In the extremophile bacterium Deinococcus radiodurans, the outermost surface layer is tightly connected with the rest of the cell wall. This integrated organization provides a compact structure that shields the bacterium against environmental stresses. The fundamental unit of this surface layer (S-layer) is the S-layer deinoxanthin-binding complex (SDBC), which binds the carotenoid deinoxanthin and provides both, thermostability and UV radiation resistance. However, the structural organization of the SDBC awaits elucidation. Here, we report the isolation of the SDBC with a gentle procedure consisting of lysozyme treatment and solubilization with the nonionic detergent n-dodecyl-β-d-maltoside, which preserved both hydrophilic and hydrophobic components of the SDBC and allows the retention of several minor subunits. As observed by low-resolution single-particle analysis, we show that the complex possesses a porin-like structural organization, but is larger than other known porins. We also noted that the main SDBC component, the protein DR_2577, shares regions of similarity with known porins. Moreover, results from electrophysiological assays with membrane-reconstituted SDBC disclosed that it is a nonselective channel that has some peculiar gating properties, but also exhibits behavior typically observed in pore-forming proteins, such as porins and ionic transporters. The functional properties of this system and its porin-like organization provide information critical for understanding ion permeability through the outer cell surface of S-layer-carrying bacterial species.
- MeSH
- bakteriální proteiny chemie genetika MeSH
- buněčná membrána chemie MeSH
- buněčná stěna chemie MeSH
- Deinococcus chemie genetika MeSH
- karotenoidy chemie MeSH
- membránové glykoproteiny chemie MeSH
- multiproteinové komplexy chemie genetika MeSH
- poriny chemie MeSH
- vazba proteinů genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
... 121 -- Certain Pairs of Domains Are Found Together in Many Proteins 122 The Human Genome Encodes a Complex ... ... Proteins -- An Elaborate Ubiquitin-Conjugating Syster- s -sec xs % Proteins -- Protein Complexes with ... ... Proteins Are Controlled by Covalent Modifications Direct Them to Specific Sites Inside the Cel A Complex ... ... Regions on the Same Chromosome Replicate at Distinct Times in S Phase 258 -- A Large Multisubunit Complex ... ... be-r Complex Connects Photosystem II to •stem I -- Carries Out the Second Charge-Separation \" *ne Z ...
Sixth edition xxxiv, 1430 stran v různém stránkování : ilustrace (převážně barevné) ; 29 cm
- Konspekt
- Biochemie. Molekulární biologie. Biofyzika
- NLK Obory
- molekulární biologie, molekulární medicína
- NLK Publikační typ
- učebnice vysokých škol
... Synthesis and Degradation of Proteins is a Fundamental Property of Cells 86 -- The Proteasome Is a Complex ... ... 226 -- DNA Transposons Are Present in Prokaryotes and Eukaryotes 227 -- LTR Retrotransposons Behave Like ... ... Initiation 296 -- Sequential Assembly of Proteins Forms the Pol II -- Transcription Preinitiation Complex ... ... 421 -- Most Transmembrane Proteins Have Membrane-Spanning a Helices 422 -- Multiple ß Strands in Porins ... ... -- Nucleus 569 -- Large and Small Molecules Enter and Leave the -- Nucleus via Nuclear Pore Complexes ...
6th ed. xxxvii, 1150 s. : il., tab. ; 29 cm
- MeSH
- biologie buňky MeSH
- molekulární biologie MeSH
- Publikační typ
- monografie MeSH
- Konspekt
- Biochemie. Molekulární biologie. Biofyzika
- NLK Obory
- biologie
- cytologie, klinická cytologie
