Abstract：
:We have probed the structure of the human mitochondrial DNA helicase, an enzyme that uses the energy of nucleotide hydrolysis to unwind duplex DNA during mitochondrial DNA replication. This novel helicase shares substantial amino acid sequence and functional similarities with the bacteriophage T7 primase-helicase. We show in velocity sedimentation and gel filtration analyses that the mitochondrial DNA helicase exists as a hexamer. Limited proteolysis by trypsin results in the production of several stable fragments, and N-terminal sequencing reveals distinct N and C-terminal polypeptides that represent minimal structural domains. Physical analysis of the proteolytic products defines the region required to maintain oligomeric structure to reside within amino acid residues approximately 405-590. Truncations of the N and C termini affect differentially DNA-dependent ATPase activity, and whereas a C-terminal domain polypeptide is functional, an N-terminal domain polypeptide lacks ATPase activity. Sequence similarity and secondary structural alignments combined with biochemical data suggest that amino acid residue R609 serves as the putative arginine finger that is essential for ATPase activity in ring helicases. The hexameric conformation and modular architecture revealed in our study document that the mitochondrial DNA helicase and bacteriophage T7 primase-helicase share physical features. Our findings place the mitochondrial DNA helicase firmly in the DnaB-like family of replicative DNA helicases.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Ziebarth TD,Farr CL,Kaguni LSdoi
10.1016/j.jmb.2007.01.079subject
Has Abstractpub_date
2007-04-13 00:00:00pages
1382-91issue
5eissn
0022-2836issn
1089-8638pii
S0022-2836(07)00156-8journal_volume
367pub_type
杂志文章abstract：:The structure of the complex between a recombinant single-chain Fv construct of antibody NC10 with a five-residue peptide linker between VH and VL (termed scFv(5)), and its antigen, tetrameric neuraminidase from influenza virus (NA), has been determined and refined at 2.5 A resolution. The antibody-antigen binding int...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1998.1794
更新日期：1998-06-19 00:00:00
abstract：:The precise geometry of the flagellar basal structure anchored in the cytoplasmic membrane was determined by digital stereo-photogrammetry of the images captured by quick-freeze deep-etch replica electron microscopy. In order to examine the structure on the periplasmic side of the membrane, we analyzed the MS ring com...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1996.0038
更新日期：1996-01-26 00:00:00
abstract：:Inhibitors of the enzymes of the lysine biosynthetic pathway are considered promising lead compounds for the design of new antibacterial drugs, because the pathway appears to be indispensable for bacteria and because it is absent in humans. As part of our efforts to structurally characterize all enzymes of this pathwa...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2007.01.023
更新日期：2007-03-30 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.08.025
更新日期：2004-10-08 00:00:00
abstract：:The ribosomal protein L30 from yeast Saccharomyces cerevisiae auto-regulates its own synthesis by binding to a structural element in both its pre-mRNA and its mRNA. The three-dimensional structures of L30 in the free (f L30) and the pre-mRNA bound (b L30) forms have been solved by nuclear magnetic resonance spectrosco...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1999.3044
更新日期：1999-09-17 00:00:00
abstract：:The foldon domain constitutes the C-terminal 30 amino acid residues of the trimeric protein fibritin from bacteriophage T4. Its function is to promote folding and trimerization of fibritin. We investigated structure, stability and folding mechanism of the isolated foldon domain. The domain folds into the same trimeric...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.02.020
更新日期：2004-04-02 00:00:00
abstract：:We investigate the conservation of amino acid residue sequences in 21 DNA-binding protein families and study the effects that mutations have on DNA-sequence recognition. The observations are best understood by assigning each protein family to one of three classes: (i) non-specific, where binding is independent of DNA ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/s0022-2836(02)00571-5
更新日期：2002-07-26 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1993.1063
更新日期：1993-02-05 00:00:00
abstract：:Mannan-binding lectin (MBL) is the archetypical pathogen recognition molecule of the innate immune defense. Upon binding to microorganisms, reactions leading to the destruction of the offender ensue. MBL is an oligomer of structural subunits each composed of three identical polypeptides. We used atomic force microscop...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2009.05.083
更新日期：2009-08-07 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2014.03.003
更新日期：2014-05-15 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1993.1634
更新日期：1993-12-05 00:00:00
abstract：:The precision of the repair of linearized plasmid DNA was analyzed using a nonsense mutation inactivated beta-glucuronidase (uidA) marker gene delivered to Nicotiana plumbaginifolia protoplasts and Nicotiana tabacum leaves. The reversions at the stop-codon allowed the reactivation of the marker gene. Here we report th...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.11.001
更新日期：2005-01-28 00:00:00
abstract：:We have been able to observe the first step in bacteriophage infection, the docking of phage lambda to its membrane receptor maltoporin, at the single-particle level. High-resolution conductance recording from a single trimeric maltoporin channel reconstituted into a planar lipid bilayer has allowed detection of the s...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2006.04.034
更新日期：2006-06-23 00:00:00
abstract：:Peptides that bind to major histocompatibility complex products (MHC) are known to exhibit certain sequence motifs which, though common, are neither necessary nor sufficient for binding: MHCs bind certain peptides that do not have the characteristic motifs and only about 30% of the peptides having the required motif, ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1997.0937
更新日期：1997-04-18 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2011.12.009
更新日期：2012-02-10 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.2000.3837
更新日期：2000-08-04 00:00:00
abstract：:The sequence RGITVNGKTYGR has been reported as part of a de novo design peptide system. This peptide folds as a beta-hairpin structure with three residues per strand and two residue turns. Asn6 side-chain, the residue in position L1 of the beta-turn, appeared to be solvent exposed, interacting only within the turn but...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1997.1347
更新日期：1997-11-07 00:00:00
abstract：:Toxin-antitoxin systems consist of a stable toxin, frequently with endonuclease activity, and a small, labile antitoxin, which sequesters the toxin into an inactive complex. Under unfavorable conditions, the antitoxin is degraded, leading to activation of the toxin and resulting in growth arrest, possibly also in bact...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2007.07.016
更新日期：2007-09-28 00:00:00
abstract：:Cataract is a lens opacification disease prevalent worldwide. Cataract-causing mutations in crystallins generally lead to the formation of light-scattering particles in the lens. However, it remains unclear for the detailed structural and pathological mechanisms of most mutations. In this study, we showed that the G12...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2015.07.001
更新日期：2015-08-28 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(84)90077-9
更新日期：1984-11-05 00:00:00
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pub_type： 杂志文章
doi：10.1016/j.jmb.2009.10.041
更新日期：2010-01-08 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/s0022-2836(02)00620-4
更新日期：2002-08-23 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.08.073
更新日期：2004-10-29 00:00:00
abstract：:A gene library was constructed coding for all possible variants of two amino acids (101, 102) in a solvent-exposed surface return loop (alpha E-beta D) of Bacillus stearothermophilus L-lactate dehydrogenase (bsLDH). All but one of 38 enzyme variants examined were thermally stable and had native-like hydrodynamic prope...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1996.0626
更新日期：1996-11-22 00:00:00
abstract：:Isolated nucleoli from exponentially growing microplasmodia of Physarum polycephalum were digested with micrococcal nuclease or DNAase I, or were photoreacted with trimethyl psoralen. In the coding region for the precursor of the ribosomal RNA, micrococcal nuclease and DNAase I digestions show predominantly a smear, a...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(87)90408-6
更新日期：1987-08-20 00:00:00
abstract：:The three-dimensional structure of a site-directed mutant of the bacterially expressed Fv fragment from monoclonal antibody D1.3, complexed to the specific antigen lysozyme has been determined to a nominal resolution of 1.8 A using X-ray diffraction data. The replacement of VL Trp92 by Asp allows two water molecules t...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1994.1309
更新日期：1994-05-13 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1997.1115
更新日期：1997-07-11 00:00:00
abstract：:The X-ray structures of two hemoglobins (Hb) from the sea cucumber Caudina arenicola (an echinoderm) have been determined: a low spin, hemichrome, monomeric Hb-C chain, and a cyanomet-liganded dimeric Hb-D chain. Attempts to obtain crystal structures of the deoxy-liganded and hemichrome forms from the same chain type ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1995.0445
更新日期：1995-08-18 00:00:00
abstract：:Protein domains represent the basic evolutionary units that form proteins. Domain duplication and shuffling by recombination are probably the most important forces driving protein evolution and hence the complexity of the proteome. While the duplication of whole genes as well as domain-encoding exons increases the abu...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.11.050
更新日期：2005-02-11 00:00:00
abstract：:The 64 x 10(3) Mr N-terminal breakage-reunion domain of the Escherichia coli DNA gyrase A protein was purified from an over-expressing strain. When complexed with the gyrase B protein, this truncated A protein has all of the enzymic properties of the full-length counterpart, although with reduced efficiency in some ca...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/S0022-2836(05)80162-7
更新日期：1990-10-20 00:00:00
