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  • OMPF
  • OMPF ( o uter m embrane p rotein f ) is among the most general E. coli porins and is, therefore, used as a reference point in discussing the structures of more specific porins such as maltoporin. (kenyon.edu)
  • The two classical porins OmpC and OmpF consist of three 16-stranded β barrels, each of which forms a channel that is restricted in the middle due to the inward folding of a loop ( 8 ). (asm.org)
  • Intrinsically disordered protein threads through the bacterial outer-membrane porin OmpF. (nih.gov)
  • phage
  • ipeX was localized within an untranslated region of 247 base pairs between the stop codon of nmpC -a remnant porin gene from the cryptic phage qsr ′ (DLP12) genome-and its predicted Rho-independent transcriptional terminator. (asm.org)
  • Another fascinating but even less understood example of porin regulation involves the lysogenization of E. coli K-12 cells by the PA-2 phage ( 28 ). (asm.org)
  • Here, the lysogenization event leads to the expression of a phage-encoded porin, Lc, and the inhibition of the host's OmpC porin. (asm.org)
  • The work conducted in this study will shed light on how phage porin expression regulates that of ompC . (asm.org)
  • oligomeric
  • The oligomeric state of native P66, elucidated by chemical cross-linking, indicated that P66 forms trimers, as do the majority of conventional porins. (diva-portal.org)
  • Thus, an intrinsically disordered protein can tunnel through the narrow pores of an oligomeric porin to deliver an epitope signal to the cell to initiate cell death. (nih.gov)
  • membrane
  • The membrane-spanning architecture of P13 was determined by epitope mapping and computer-based structural predictions which revealed that P13 is an unusual porin, not possessing the structural properties of conventional porins: rather than forming β-barrels, it is predicted to span the membrane with hydrophobic α-helices. (diva-portal.org)
  • This family contains bacterial outer membrane porins with serine protease activity [ PMID: 9636669 ]. (ebi.ac.uk)
  • A generally accepted view of the porin assembly pathway is that after the removal of the signal peptide from precursors, mature porin molecules transiently exist in the periplasm as soluble or peripherally membrane-associated, thermolabile intermediates. (asm.org)
  • The outer membrane porins such as OmpK35 and OmpK36 were analysed by SDS-PAGE, PCR, and sequencing methods. (hindawi.com)
  • Outer membrane porin, OmpK35, was detected in 30 (62.5%) of 48 ESBL-producing isolates while OmpK36 was found in 35 (72.91%) of 48 ESBL-producing isolates. (hindawi.com)
  • We present here current measurements through porins from reconstituted outer membrane, which demonstrate that bacterial metabolites, the MDO's, which bathe the periplasmic side of the outer membrane, induce the channels to close. (nih.gov)
  • The neisserial porins are the major protein components of the outer membrane of the pathogenic Neisseria (N. meningitidis and N. gonorrhoeae). (rupress.org)
  • A bacterium producing altered porins that block passage of the antibiotic through the outer membrane of a gram-negative bacterium. (ccbcmd.edu)
  • In silico analyzes of porins involved in niche adaptation: Exploring the role of Helicobacter pylori outer membrane phospholipase A in acid tolerance. (uio.no)
  • pores formed
  • Further information on the structure of the pores formed by the different porins from Salmonella was obtained from the selectivity for various ions. (nih.gov)
  • mutant
  • Finally, the biological relevance of two porins, P13 and P66, was demonstrated in a double mutant displaying a stress response as revealed by increased sensitivity to high osmolarity and elevated expression of the B. burgdorferi heat-shock protein HtrA homolog. (diva-portal.org)
  • This mutant porin and its derivative, OmpC R74C,G154C , or OmpC 2Cys ( 17 ), are the subjects of this work and are further discussed below. (asm.org)
  • channels
  • Most porins form general, non-specific channels that are regulated by environmental changes. (kenyon.edu)
  • By demanding bacterial growth on sugars too large to normally diffuse through porin channels, alterations in the channel loop resulting in functionally large channels were obtained ( 19 ). (asm.org)
  • Some electrophysiological studies find reconstituted porins in a mostly open state, while those done with the patch-clamp technique performed on live cells suggest that the vast majority of the native channels are closed. (nih.gov)
  • Paper I: In Silico Structure and Sequence Analysis of Bacterial Porins and Specific Diffusion Channels for Hydrophilic Molecules: Conservation, Multimericity and Multifunctionality. (uio.no)
  • Structures
  • It has been possible to isolate a number porins in their active forms and generate monomer crystal structures. (kenyon.edu)
  • Porins have also served as excellent models to study OMP assembly because they are abundant and a great deal is known about their genetics, biochemistry, and structures. (asm.org)
  • sequence
  • Maltoporin is also one of the many porins which contains a bacteriophage recognition sequence. (kenyon.edu)
  • Although there is little to no sequence homology among porins, they often share a strong structural resemblance. (kenyon.edu)
  • interactions
  • To explore the basis of their potent adjuvant activity, the effect of the neisserial porins on T-B cell interactions and T cell costimulation was examined. (rupress.org)
  • nutrients
  • The growth rate of Mycobacterium smegmatis depends on sufficient porin-mediated influx of nutrients. (sigmaaldrich.com)
  • These results show that porin-mediated influx of nutrients is a major determinant of the growth rate of M. smegmatis. (sigmaaldrich.com)
  • sequences
  • These sequences are putative porins. (ebi.ac.uk)
  • Interestingly, another prophage, PA-2, which encodes a porin similar to NmpC, known as Lc, has sequences downstream from lc identical to that of ipeX . (asm.org)
  • unusual
  • There also have been reports of some unusual and less well-understood mechanisms of porin regulation. (asm.org)
  • Mechanism
  • Upregulation of B7-2 on the surface of B lymphocytes may be the mechanism behind the immunopotentiating activity of neisserial porins. (rupress.org)