Predicted topology of the N-terminal domain of the hydrophilic subunit of the mannose transporter of Escherichia coli.
A folding topology for the homodimeric N-terminal domain (IIA, 2 x 14 kDa) of the hydrophilic subunit (IIABman) of the mannose transporter of E. coli is proposed. The prediction is based on (i) tertiary structure prediction methods, and (ii) functional properties of site-directed mutants in correlation with NMR-derived alpha/beta secondary structure data. The 3D structure profile suggested that the overall fold of IIA is similar to that of the unrelated protein, flavodoxin, which is an open-stranded parallel beta-sheet with a strand order of 5 4 3 1 2. The 3D model of IIA, constructed using the known atomic structure of flavodoxin, is consistent with the results from site-directed mutagenesis. Recently NMR results confirmed the open parallel beta-sheet with a strand order of 4 3 1 2 (residues 1-120) of our model whereas beta-strand 5 (residues 127-130) was shown to be antiparallel to beta-strand 4. The correctly predicted fold includes 90% of the monomeric subunit sequence and contains all functional sites of the IIA domain.
Marković-Housley
Z
Z
Institut für Biochemie, Universität Bern, Switzerland.
Balbach
J
J
Stolz
B
B
Génovésio-Taverne
J C
JC
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose; D037241:Mannose-Binding Lectins; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D002352:Carrier Proteins; D037241:Mannose-Binding Lectins; D008358:Mannose