Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

TolR is a part of the Pal/Tol system which forms a five-member, membrane-spanning, multiprotein complex that is conserved in Gram-negative bacteria. The Pal/Tol system helps to maintain the integrity of the outer membrane and has been proposed to be involved in several other cellular processes including cell division. Obtaining the structure of TolR is of interest not only to help explain the many proposed functions of the Pal/Tol system but also to gain an understanding of the TolR homologues ExbD and MotB and to provide more targets for antibacterial treatments. In addition, the structure may provide insights into how colicins and bacteriophages are able to enter the cell. Here we report the solution structure of the homodimeric periplasmic domain of TolR from Haemophilus influenzae, determined with conventional, NOE-based NMR spectroscopy, supplemented by extensive residual dipolar coupling measurements. A novel method for assembling the dimer from small-angle X-ray scattering data confirms the NMR-derived structure. To facilitate NMR spectral analysis, a TolR construct containing residues 59-130 of the 139-residue protein was created. The periplasmic domain of TolR forms a C 2-symmetric dimer consisting of a strongly curved eight-stranded beta-sheet, generating a large deep groove on one side, while four helices cover the other face of the sheet. The structure of the TolR dimer together with data from the literature suggests how the periplasmic domain of TolR is most likely oriented relative to the cytoplasmic membrane and how it may interact with other components of the Pal/Tol system, particularly TolQ.
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PMID:The periplasmic domain of TolR from Haemophilus influenzae forms a dimer with a large hydrophobic groove: NMR solution structure and comparison to SAXS data. 1826 47

This study evaluated the vaccination response to Haemophilus influenzae type b (Hib) in malnourished pregnant women (MN), cord blood (CB) and in infants at two and six months of age for comparison with a control group (C). Twenty-eight malnourished pregnant women and 29 pregnant controls were immunized with conjugated Act-HIB(R) in the third trimester of pregnancy. Blood samples were collected from all before the immunization, during labor (post immunization), and from CB. All infants were immunized with Hib vaccine according to normal vaccine schedule and sera were collected at two and six months of age. Antibody levels to polyribosylribitol phosphate (PRP) were similar for both groups. Preimmunization: MN 1.94 microg/mL, C 1.68 microg/mL; post-vaccination: MN 18.53 microg/mL and C 17.55 microg/mL; in CB from MN 14.46 microg/mL and from C 17.04 microg/mL. Infants from MN and C mothers presented respectively at two months: 5.18 microg/mL and 8.60 microg/mL and at six months: MN 3.42 microg/mL and C 2.18 microg/mL. Antibody levels were similar in both groups studied (p = 0.485), however the vertical transmission rate was 14% lower in the MN pregnant group. Levels of antibodies > 0.15 microg/mL were found in all newborns from the MN pregnant group. Pregnant MN presented an immunological response to Hib vaccine similar to group C, however, vertical transmission rate of antibodies to PRP in the MN pregnant group was 14% lower than that in C, suggesting a less efficient passage of antibodies within this group.
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PMID:Placental transfer of Haemophilus influenzae type b antibodies in malnourished pregnant women. 1855 14

HI0381 of Haemophilus influenzae was investigated by circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. HI0381 is a 153-residue peptidoglycan-associated outer membrane lipoprotein, and a part of the larger Tol/Pal network. Here, we report its backbone (1)H, (15)N, and (13)C resonance assignments, and secondary structure predictions. About 97% of all of the (1)HN, (15)N, (13)CO, (13)C alpha, and (13)C beta resonances covering 131 non-proline residues of the 134 residue, mature protein, were clarified by sequential and specific assignments. CSI and TALOS analyses revealed that HI0381 contains five alpha-helices and five beta-strands. To characterize the structure of HI0381, the effects of pH and salt concentration were investigated by CD. In addition, the structural changes occurring when HI0381 was in a membranous environment were investigated by comparing its HSQC spectra and CD data in buffer and in DPC micelles; the results showed that helix alpha 4 and strand beta 4 became aligned with the membrane. We conclude that the conformation of HI0381 is affected by the membrane environment, implying that its folded state is directly related to its function.
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PMID:Localization of the membrane interaction sites of Pal-like protein, HI0381 of Haemophilus influenzae. 1859 13