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Novel structure and nucleotide binding properties of HI1480 from Haemophilus influenzae: a protein with no known sequence homologues.
- Source :
-
Proteins [Proteins] 2004 Aug 15; Vol. 56 (3), pp. 564-71. - Publication Year :
- 2004
-
Abstract
- The crystal structure of the Haemophilus influenzae protein HI1480 was determined at 2.1-A resolution. The amino acid sequence of HI1480 is unique, having no homology with other known protein sequences. The protein adopts a novel alpha+beta fold, and associates into a dimer of tightly associated dimers. The tight dimers are formed by intermolecular interactions that are mediated by an antiparallel beta-barrel involving both monomers. Helical regions of two dimers mediate the tetramer formation. The helical region contains a four-helix bundle that has been seen only in the anticodon binding domains of class I tRNA synthetases. A cluster of four residues, Tyr18, Arg134, Glu26, and Lys12 is located in a depression formed at the four-helix bundle/ beta-barrel interface. The arrangement is suggestive of an active center, possibly a catalytic site. The HI1480 gene is located within the Mu-like prophage region of H. influenzae, has no homology to bacteriophage genes, and is flanked by transposases. Hence, this is an example of horizontal transfer from an unknown organism. Gel mobility shift assays revealed that HI1480 binds DNA and RNA molecules. Double-stranded DNA is favored over single-stranded DNA, and longer DNA molecules are bound better than shorter ones.<br /> (Copyright 2004 Wiley-Liss, Inc.)
- Subjects :
- Amino Acid Sequence
Bacterial Proteins genetics
Bacterial Proteins physiology
Base Sequence
Binding Sites
Crystallization
Crystallography, X-Ray
DNA-Binding Proteins chemistry
DNA-Binding Proteins genetics
Electrophoretic Mobility Shift Assay
Haemophilus influenzae genetics
Models, Molecular
Molecular Sequence Data
Multiprotein Complexes chemistry
Protein Structure, Secondary
RNA-Binding Proteins chemistry
RNA-Binding Proteins genetics
Selenomethionine chemistry
Sequence Homology, Amino Acid
Bacterial Proteins chemistry
Haemophilus influenzae chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1097-0134
- Volume :
- 56
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Proteins
- Publication Type :
- Academic Journal
- Accession number :
- 15229888
- Full Text :
- https://doi.org/10.1002/prot.20148