Localization of the membrane interaction sites of Pal-like protein, HI0381 of Haemophilus influenzae.
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.
Kang
Su-Jin
SJ
Innovative Drug Research Center for Metabolic and Inflammatory Disease, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea.
Park
Sung Jean
SJ
Lee
Bong-Jin
BJ
D000429:Alcohol Oxidoreductases / Q000737:chemistry*; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary
D001425:Bacterial Outer Membrane Proteins; D008823:Micelles; D000429:Alcohol Oxidoreductases; C022641:Shikimate dehydrogenase