Caulobacter crescentus cell envelope: effect of growth conditions on murein and outer membrane protein composition.

In an attempt to elucidate the relation between Micrococcus cryophilus, Neisseria caviae, Neisseria ovis, and Branhamella catarrhalis, fractions derived from outer membranes of a strain of each organism were examined for protein composition by SDS – polyacrylamide gel electrophoresis. Micrococcus cryophilus outer membrane protein showed extensive similarities to that of N. ovis and contained a heat-modifiable protein which behaved almost identically with the corresponding bands previously shown to exist in N. caviae and N. oris. Branhamella catarrhalis protein was distinctly different from those of M. cryophilus and the two 'false neisserias' N. caviae and N. oris.

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Outer Membrane Protein Composition in Disease Isolates of Haemophilus influenzae : Pathogenic and Epidemiological Implications

Infection and Immunity ◽

10.1128/iai.30.3.709-717.1980 ◽

1980 ◽

Vol 30 (3) ◽

pp. 709-717

Author(s):

Marilyn R. Loeb ◽

David H. Smith

Keyword(s):

Membrane Proteins ◽

Membrane Protein ◽

Haemophilus Influenzae ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Outer Membrane Proteins ◽

Protein Composition ◽

The Other ◽

Major Protein ◽

Single Strain

The outer membrane protein composition of 50 disease isolates of Haemophilus influenzae has been determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. All strains, including 28 strains of serotype b , one strain each of serotypes a, c, d, e , and f , and 17 untypable strains, had an outer membrane protein composition typical of gram-negative bacteria, i.e., these membranes contained two to three dozen proteins with four to six proteins accounting for most of their protein content. Variation in the mobility of these major outer membrane proteins from strain to strain was common but not universal; the observed patterns provided useful data and new insight into the epidemiology of type b disease. The basic findings can be summarized as follows: (i) All 50 strains possessed three proteins (one minor and two major) each having identical mobilities. The other proteins, both major and minor, varied in mobility. (ii) All type b strains possessed a fourth (major) protein of identical mobility. (iii) The 28 type b strains, on the basis of the mobility of the six major outer membrane proteins, could be divided into eight subtypes. Of all the other strains examined, both typable and untypable, only the serotype a strain belonged to one of these subtypes. (iv) The untypable strains showed considerable variation in the mobilities of their major outer membrane proteins. Of these 17 strains, 13 had an additional major outer membrane protein not present in encapsulated strains. (v) The outer membrane protein composition of a single strain remained unchanged after many passages on solid media, but varied with the growth phase. (vi) The outer membrane protein composition of isolates obtained from nine patients during an epidemic of type b meningitis varied, indicating that a single strain was not responsible for the epidemic. At least five different strains were responsible for these nine cases. (vii) Identical outer membrane protein compositions were observed in the following: in a type b strain and a mutant of this strain deficient in capsule production, indicating that the level of capsule synthesis is not obviously related to outer membrane protein composition; in type b strains isolated from different anatomic sites of patients acutely ill with meningitis, indicating that the strain associated with bacteremia is the same as that isolated from the cerebrospinal fluid; in type b strains isolated from siblings who contracted meningitis at about the same time, indicating infection with the same strain; and in type b strains isolated from the initial and repeat infection of a single patient, suggesting that reinfection was due to the same strain.

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ExbBD-Dependent Transport of Maltodextrins through the Novel MalA Protein across the Outer Membrane of Caulobacter crescentus

Journal of Bacteriology ◽

10.1128/jb.187.24.8300-8311.2005 ◽

2005 ◽

Vol 187 (24) ◽

pp. 8300-8311 ◽

Cited By ~ 76

Author(s):

Heidi Neugebauer ◽

Christina Herrmann ◽

Winfried Kammer ◽

Gerold Schwarz ◽

Alfred Nordheim ◽

...

Keyword(s):

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Caulobacter Crescentus ◽

Vitamin B ◽

Wild Type ◽

E Coli ◽

Iron Source ◽

Maltose Transport ◽

Dependent Transport

ABSTRACT Analysis of the genome sequence of Caulobacter crescentus predicts 67 TonB-dependent outer membrane proteins. To demonstrate that among them are proteins that transport nutrients other than chelated Fe3+ and vitamin B12—the substrates hitherto known to be transported by TonB-dependent transporters—the outer membrane protein profile of cells grown on different substrates was determined by two-dimensional electrophoresis. Maltose induced the synthesis of a hitherto unknown 99.5-kDa protein, designated here as MalA, encoded by the cc2287 genomic locus. MalA mediated growth on maltodextrins and transported [14C]maltodextrins from [14C]maltose to [14C]maltopentaose. [14C]maltose transport showed biphasic kinetics, with a fast initial rate and a slower second rate. The initial transport had a Kd of 0.2 μM, while the second transport had a Kd of 5 μM. It is proposed that the fast rate reflects binding to MalA and the second rate reflects transport into the cells. Energy depletion of cells by 100 μM carbonyl cyanide 3-chlorophenylhydrazone abolished maltose binding and transport. Deletion of the malA gene diminished maltose transport to 1% of the wild-type malA strain and impaired transport of the larger maltodextrins. The malA mutant was unable to grow on maltodextrins larger than maltotetraose. Deletion of two C. crescentus genes homologous to the exbB exbD genes of Escherichia coli abolished [14C]maltodextrin binding and transport and growth on maltodextrins larger than maltotetraose. These mutants also showed impaired growth on Fe3+-rhodotorulate as the sole iron source, which provided evidence of energy-coupled transport. Unexpectedly, a deletion mutant of a tonB homolog transported maltose at the wild-type rate and grew on all maltodextrins tested. Since Fe3+-rhodotorulate served as an iron source for the tonB mutant, an additional gene encoding a protein with a TonB function is postulated. Permeation of maltose and maltotriose through the outer membrane of the C. crescentus malA mutant was slower than permeation through the outer membrane of an E. coli lamB mutant, which suggests a low porin activity in C. crescentus. The pores of the C. crescentus porins are slightly larger than those of E. coli K-12, since maltotetraose supported growth of the C. crescentus malA mutant but failed to support growth of the E. coli lamB mutant. The data are consistent with the proposal that binding of maltodextrins to MalA requires energy and MalA actively transports maltodextrins with Kd values 1,000-fold smaller than those for the LamB porin and 100-fold larger than those for the vitamin B12 and ferric siderophore outer membrane transporters. MalA is the first example of an outer membrane protein for which an ExbB/ExbD-dependent transport of a nutrient other than iron and vitamin B12 has been demonstrated.

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Structure of BamA, an essential factor in outer membrane protein biogenesis

Acta Crystallographica Section D Biological Crystallography ◽

10.1107/s1399004714007482 ◽

2014 ◽

Vol 70 (6) ◽

pp. 1779-1789 ◽

Cited By ~ 64

Author(s):

Reinhard Albrecht ◽

Monika Schütz ◽

Philipp Oberhettinger ◽

Michaela Faulstich ◽

Ivan Bermejo ◽

...

Keyword(s):

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Cell Envelope ◽

Significant Degree ◽

State Function ◽

E Coli ◽

Functional Studies ◽

C Terminus ◽

Protein Biogenesis

Outer membrane protein (OMP) biogenesis is an essential process for maintaining the bacterial cell envelope and involves the β-barrel assembly machinery (BAM) for OMP recognition, folding and assembly. InEscherichia colithis function is orchestrated by five proteins: the integral outer membrane protein BamA of the Omp85 superfamily and four associated lipoproteins. To unravel the mechanism underlying OMP folding and insertion, the structure of theE. coliBamA β-barrel and P5 domain was determined at 3 Å resolution. These data add information beyond that provided in the recently published crystal structures of BamA fromHaemophilus ducreyiandNeisseria gonorrhoeaeand are a valuable basis for the interpretation of pertinent functional studies. In an `open' conformation,E. coliBamA displays a significant degree of flexibility between P5 and the barrel domain, which is indicative of a multi-state function in substrate transfer.E. coliBamA is characterized by a discontinuous β-barrel with impaired β1–β16 strand interactions denoted by only two connecting hydrogen bonds and a disordered C-terminus. The 16-stranded barrel surrounds a large cavity which implies a function in OMP substrate binding and partial folding. These findings strongly support a mechanism of OMP biogenesis in which substrates are partially folded inside the barrel cavity and are subsequently released laterally into the lipid bilayer.

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The ner Gene of Photorhabdus: Effects on Primary-Form-Specific Phenotypes and Outer Membrane Protein Composition

Journal of Bacteriology ◽

10.1128/jb.184.14.4048.2002 ◽

2002 ◽

Vol 184 (14) ◽

pp. 4048-4048

Author(s):

Keith H. O'Neill ◽

Declan M. Roche ◽

David J. Clarke ◽

Barbara C. A. Dowds

Keyword(s):

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Protein Composition ◽

Primary Form

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Conserved features and major differences in the outer membrane protein composition of chlamydiae

Environmental Microbiology ◽

10.1111/1462-2920.12621 ◽

2014 ◽

Vol 17 (4) ◽

pp. 1397-1413 ◽

Cited By ~ 11

Author(s):

Karin Aistleitner ◽

Dorothea Anrather ◽

Thomas Schott ◽

Julia Klose ◽

Monika Bright ◽

...

Keyword(s):

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Protein Composition

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AN OUTER MEMBRANE PROTEIN OF NEISSERIA MENINGITIDIS GROUP B RESPONSIBLE FOR SEROTYPE SPECIFICITY

Journal of Experimental Medicine ◽

10.1084/jem.140.1.87 ◽

1974 ◽

Vol 140 (1) ◽

pp. 87-104 ◽

Cited By ~ 48

Author(s):

Carl E. Frasch ◽

Emil C. Gotschlich

Keyword(s):

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Cell Envelope ◽

Polyacrylamide Gel Electrophoresis ◽

Gel Filtration ◽

Major Outer Membrane Protein ◽

Antigenic Specificity ◽

Group B

Meningococcal groups B and C have been subdivided into a series of serotypes based upon the antigenic specificity of protein serotype antigens (STA). The purpose of these studies was to obtain the STA by gentle methods and determine its anatomic location in the meningococcal cell. The STA was extracted from group B meningococcal strains by either 0.2 M LiCl or 0.2 M CaCl2 and isolated from the extracts by gel filtration on Sepharose 6B or by pelleting the STA by centrifugation at 100,000 g. The isolated STA was a lipoprotein-lipopolysaccharide complex with a mol wt of approximately 4 x 106 daltons. Antisera prepared against the type 2 STA were bactericidal only for homologous serotype strains. The STA proved to be a constituent of the outer membrane of the cell envelope. This was shown by SDS-polyacrylamide gel electrophoresis (PAGE) of the isolated outer membrane and of the purified STA. The type 2 STA complex contains three principal proteins, one of which is predominant with a mol wt of 41,000 daltons. The type 2 STA was dissociated by Triton X-100 and separated by sucrose gradient isodensity centrifugation into two peaks. The denser peak (ρ = 1.26 g/cm3) contained the majority of the 41,000 dalton major outer membrane protein as shown by SDS-PAGE. This peak also contained the type 2 antigenic determinant. Thus the major outer membrane protein, extracted as part of a lipoprotein-lipopolysaccharide complex, contains the type 2 STA determinant.

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