title: Crystal structure of the DUF16 domain of MPN010 from Mycoplasma pneumoniae.
abstract: We have determined the crystal structure of the DUF16 domain of unknown function encoded by the gene MPN010 of Mycoplasma pneumoniae at 1.8 A resolution. The crystal structure revealed that this domain is composed of two separated homotrimeric coiled-coils. The shorter one consists of 11 highly conserved residues. The sequence comprises noncanonical heptad repeats that induce a right-handed coiled-coil structure. The longer one is composed of approximately nine heptad repeats. In this coiled-coil structure, there are three distinguishable regions that confer unique structural properties compared with other known homotrimeric coiled-coils. The first part, containing one stutter, is an unusual phenylalanine-rich region that is not found in any other coiled-coil structures. The second part is a highly conserved glutamine-rich region, frequently found in other trimeric coiled-coil structures. The last part is composed of prototype heptad repeats. The phylogenetic analysis of the DUF16 family together with a secondary structure prediction shows that the DUF16 family can be classified into five subclasses according to N-terminal sequences. Based on the structural comparison with other coiled-coil structures, a probable molecular function of the DUF16 family is discussed.
authors.affiliation: College of Pharmacy, Ewha Womans Unversity, Seoul 120-750, Korea.
authors.forename: Dong Hae
authors.initials: DH
authors.lastname: Shin
authors.forename: Jeong-Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Hisao
authors.initials: H
authors.lastname: Yokota
authors.forename: Rosalind
authors.initials: R
authors.lastname: Kim
authors.forename: Sung-Hou
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D009177:Mycoplasma pneumoniae / Q000737:chemistry* / Q000201:enzymology; D010802:Phylogeny; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017421:Sequence Analysis