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Full-Text Articles in Molecular Biology

Characterization And Structure Of A Zn2+ And [2fe-2s]-Containing Copper Chaperone From Archaeoglobus Fulgidus, Matthew H. Sazinsky, Benjamin Lemoine, Maria Orofino, Roman Davydov, Krisztina Z. Bencze, Timothy L. Stemmler, Brian M. Hoffman, José M. Argüello, Amy C. Rosenzweig Jul 2007

Characterization And Structure Of A Zn2+ And [2fe-2s]-Containing Copper Chaperone From Archaeoglobus Fulgidus, Matthew H. Sazinsky, Benjamin Lemoine, Maria Orofino, Roman Davydov, Krisztina Z. Bencze, Timothy L. Stemmler, Brian M. Hoffman, José M. Argüello, Amy C. Rosenzweig

Biochemistry and Molecular Biology Faculty Publications

Bacterial CopZ proteins deliver copper to P1B-type Cu+-ATPases that are homologous to the human Wilson and Menkes disease proteins. The genome of the hyperthermophile Archaeoglobus fulgidus encodes a putative CopZ copper chaperone that contains an unusual cysteine rich N-terminal domain of 130 amino acids in addition to a C-terminal copper-binding domain with a conserved CXXC motif. The N-terminal domain (CopZ-NT) is homologous to proteins found only in extremophiles and is the only such protein that is fused to a copper chaperone. Surprisingly, optical, electron paramagnetic resonance, and X-ray absorption spectroscopic data indicate the presence of a [2Fe-2S] cluster in CopZ-NT. …


Human Frataxin: Iron And Ferrochelatase Binding Surface, Krisztina Z. Bencze, Taejin Yoon, CéSar MilláN-Pacheco, Patrick B. Bradley, Nina Pastor, J. A. Cowan, Timothy L. Stemmler May 2007

Human Frataxin: Iron And Ferrochelatase Binding Surface, Krisztina Z. Bencze, Taejin Yoon, CéSar MilláN-Pacheco, Patrick B. Bradley, Nina Pastor, J. A. Cowan, Timothy L. Stemmler

Biochemistry and Molecular Biology Faculty Publications

The coordinated iron structure and ferrochelatase binding surface of human frataxin have been characterized to provide insight into the protein’s ability to serve as the iron chaperone during heme biosynthesis.


The Structure And Function Of Frataxin, Krisztina Z. Bencze, Kalyan C. Kondapalli, Jeremy D. Cook, Stephen Mcmahon, César Millán-Pacheco, Nina Pastor, Timothy L. Stemmler Oct 2006

The Structure And Function Of Frataxin, Krisztina Z. Bencze, Kalyan C. Kondapalli, Jeremy D. Cook, Stephen Mcmahon, César Millán-Pacheco, Nina Pastor, Timothy L. Stemmler

Biochemistry and Molecular Biology Faculty Publications

Frataxin, a highly conserved protein found in prokaryotes and eukaryotes, is required for efficient regulation of cellular iron homeostasis. Humans with a frataxin deficiency have the cardio- and neurodegenerative disorder Friedreich’s ataxia, commonly resulting from a GAA trinucleotide repeat expansion in the frataxin gene. While frataxin’s specific function remains a point of controversy, a general consensus is the protein assists in controlling cellular iron homeostasis by directly binding iron. This review focuses on the structural and biochemical aspects of iron binding by the frataxin orthologs and outlines molecular attributes that may help explain the protein’s role in different cellular pathways.


Three-Dimensional Structure Of The Bacterial Cell Wall Peptidoglycan, Samy O. Meroueh, Krisztina Z. Bencze, Dusan Hesek, Mijoon Lee, Timothy L. Stemmler, Shahriar Mobashery Mar 2006

Three-Dimensional Structure Of The Bacterial Cell Wall Peptidoglycan, Samy O. Meroueh, Krisztina Z. Bencze, Dusan Hesek, Mijoon Lee, Timothy L. Stemmler, Shahriar Mobashery

Biochemistry and Molecular Biology Faculty Publications

The 3D structure of the bacterial peptidoglycan, the major constit- uent of the cell wall, is one of the most important, yet still unsolved, structural problems in biochemistry. The peptidoglycan comprises alternating N-acetylglucosamine (NAG) and N-acetylmu- ramic disaccharide (NAM) saccharides, the latter of which has a peptide stem. Adjacent peptide stems are cross-linked by the transpeptidase enzymes of cell wall biosynthesis to provide the cell wall polymer with the structural integrity required by the bacte- rium. The cell wall and its biosynthetic enzymes are targets of antibiotics. The 3D structure of the cell wall has been elusive because of its …


The Importance Of A Critical Protonation State And The Fate Of The Catalytic Steps In Class A Β-Lactamases And Penicillin-Binding Proteins, Dasantila Golemi-Kotra, Samy O. Meroueh, Choonkeun Kim, Sergei B. Vakulenko, Alexey Bulychev, Ann J. Stemmler, Timothy L. Stemmler, Shahriar Mobashery May 2004

The Importance Of A Critical Protonation State And The Fate Of The Catalytic Steps In Class A Β-Lactamases And Penicillin-Binding Proteins, Dasantila Golemi-Kotra, Samy O. Meroueh, Choonkeun Kim, Sergei B. Vakulenko, Alexey Bulychev, Ann J. Stemmler, Timothy L. Stemmler, Shahriar Mobashery

Biochemistry and Molecular Biology Faculty Publications

b-Lactamases and penicillin-binding proteins are bacterial enzymes involved in antibiotic resistance to b-lactam antibiotics and biosynthetic assembly of cell wall, respectively. Members of these large families of enzymes all experience acylation by their respective substrates at an active-site serine as the first step in their catalytic activities. A Ser-X-X-Lys sequence motif is seen in all these proteins and crystal structures demonstrate that the side chain functions of the serine and lysine are in contact with one another. Three independent methods were used in this report to address the question of the protonation state of this important lysine (Lys73) in the …


Purified Particulate Methane Monooxygenase From Methylococcus Capsulatus (Bath) Is A Dimer With Both Mononuclear Copper And A Copper-Containing Cluster, Raquel L. Lieberman, Deepak B. Shrestha, Peter E. Doan, Brian M. Hoffman, Timothy L. Stemmler, Amy C. Rosenzweig Mar 2003

Purified Particulate Methane Monooxygenase From Methylococcus Capsulatus (Bath) Is A Dimer With Both Mononuclear Copper And A Copper-Containing Cluster, Raquel L. Lieberman, Deepak B. Shrestha, Peter E. Doan, Brian M. Hoffman, Timothy L. Stemmler, Amy C. Rosenzweig

Biochemistry and Molecular Biology Faculty Publications

Particulate methane monooxygenase (pMMO) is a membrane-bound enzyme that catalyzes the oxidation of methane to methanol in methanotropic bacteria. Understanding how this enzyme hydroxylates methane at ambient temperature and pressure is of fundamental chemical and potential commercial importance. Difficulties in solubilizing and purifying active pMMO have led to conflicting reports regarding its biochemical and biophysical properties, however. We have purified pMMO from Methylococcus capsulatus (Bath) and detected activity. The purified enzyme has a molecular mass of ~200 kDa, probably corresponding to an a2b2g2 polypeptide arrangement. Each 200 kDa pMMO complex contains 4.8 ± 0.8 copper ions and 1.5 ± 0.7 …


The Crystal Structure Of Recombinant Human Neutrophil-Activating Peptide-2 (M6l) At 1.9-Å Resolution, Michael G. Malkowski, Jean Yang Wu, Jerome B. Lazar, Paul H. Johnson, Brian Fp Edwards Mar 1995

The Crystal Structure Of Recombinant Human Neutrophil-Activating Peptide-2 (M6l) At 1.9-Å Resolution, Michael G. Malkowski, Jean Yang Wu, Jerome B. Lazar, Paul H. Johnson, Brian Fp Edwards

Biochemistry and Molecular Biology Faculty Publications

Neutrophil-activating peptide-2 (NAP-2) is a 70-residue carboxyl-terminal fragment of platelet basic protein, which is found in the a-granules of human platelets. NAP-2, which belongs to the CXC family of chemokines that includes Interleukin-B and platelet factor 4, binds to the interleukin-8 type II receptor and induces a rise in cytosolic calcium, chemotaxis of neutrophils, and exocytosis. Crystals of recombinant NAP-2 in which the single methionine at position 6 was replaced by leucine to facilitate expression belong to space group PI (unit cell parameters a = 40.8, b = 43.8, and c = 44.7 A and a = 98.4°, fl = …


The Structure Of A Complex Of Bovine Ɑ-Thrombin And Recombinant Hirudin At 2.8-Å Resolution, Jacqueline Vitali, Philip D. Martin, Michael G. Malkowski, William D. Robertson, Jerome B. Lazar, Richard C. Winant, Paul H. Johnson, Brian Fp Edwards Sep 1992

The Structure Of A Complex Of Bovine Ɑ-Thrombin And Recombinant Hirudin At 2.8-Å Resolution, Jacqueline Vitali, Philip D. Martin, Michael G. Malkowski, William D. Robertson, Jerome B. Lazar, Richard C. Winant, Paul H. Johnson, Brian Fp Edwards

Biochemistry and Molecular Biology Faculty Publications

Crystals of the complex of bovine alpha-thrombin with recombinant hirudin variant 1 have space group C222(1) with cell constants a = 59.11, b = 102.62, and c = 143.26 A. The orientation and position of the thrombin component was determined by molecular replacement and the hirudin molecule was fit in 2 magnitude of Fo - magnitude of Fc electron density maps. The structure was refined by restrained least squares and simulated annealing to R = 0.161 at 2.8-A resolution. The binding of hirudin to thrombin is generally similar to that observed in the crystals of human thrombin-hirudin. Several differences in …


The Structure Of Residues 7-16 Of The Aɑ-Chain Of Human Fibrinogen Bound To Bovine Thrombin At 2.3 Å Resolution, Philip D. Martin, William Robertson, Dusan Turk, Robert Huber, Wolfram Bode, Brian Fp Edwards Apr 1992

The Structure Of Residues 7-16 Of The Aɑ-Chain Of Human Fibrinogen Bound To Bovine Thrombin At 2.3 Å Resolution, Philip D. Martin, William Robertson, Dusan Turk, Robert Huber, Wolfram Bode, Brian Fp Edwards

Biochemistry and Molecular Biology Faculty Publications

The tetradecapeptide Ac-D-F-L-A-E-G-G-G-V-R-G-P-R-V-OMe, which mimics residues 7f-20f of the A alpha-chain of human fibrinogen, has been co-crystallized with bovine thrombin from ammonium sulfate solutions in space group P2(1) with unit cell dimensions of a = 83.0 A, b = 89.4 A, c = 99.3 A, and beta = 106.6 degrees. Three crystallographically independent complexes were located in the asymmetric unit by molecular replacement using the native bovine thrombin structure as a model. The standard crystallographic R-factor is 0.167 at 2.3-A resolution. Excellent electron density could be traced for the decapeptide, beginning with Asp-7f and ending with Arg-16f in the active …


Structural Changes That Accompany The Reduced Catalytic Efficiency Of Two Semisynthetic Ribonuclease Analogs, V. Srini J. De Mel, Philip D. Martin, Marilynn S. Doscher, Brian Fp Edwards Jan 1992

Structural Changes That Accompany The Reduced Catalytic Efficiency Of Two Semisynthetic Ribonuclease Analogs, V. Srini J. De Mel, Philip D. Martin, Marilynn S. Doscher, Brian Fp Edwards

Biochemistry and Molecular Biology Faculty Publications

The structures of two catalytically defective semi-synthetic RNases obtained by replacing aspartic acid 121 with asparagine or alanine have been determined and refined at a resolution of 2.0 A (R = 0.186 and 0.172, respectively). When these structures are compared with the refined 1.8-A structure (R = 0.204) of the fully active aspartic acid-containing enzyme (Martin, P.D., Doscher, M.S., and Edwards, B. F. P. (1987) J. Biol. Chem. 262, 15930-15938), numerous and widespread changes, much greater in number and magnitude than the small structural variations noted previously between the semisynthetic complex and RNase A, are found to have occurred. These …


The Three-Dimensional Structure Of Bovine Platelet Factor 4 At 3.0-Å Resolution, Robert St. Charles, Daniel A. Walz, Brian Fp Edwards Feb 1989

The Three-Dimensional Structure Of Bovine Platelet Factor 4 At 3.0-Å Resolution, Robert St. Charles, Daniel A. Walz, Brian Fp Edwards

Biochemistry and Molecular Biology Faculty Publications

Platelet factor 4 (PF4), which is released by platelets during coagulation, binds very tightly to negatively charged oligosaccharides such as heparin. To date, six other proteins are known that are homologous in sequence with PF4 but have quite different functions. The structure of a tetramer of bovine PF4 complexed with one Ni(CN)42− molecule has been determined at 3.0 Å resolution and refined to an R factor of 0.28. The current model contains residues 24–85, no solvent, and one overall temperature factor. Residues 1–13, which carried an oligosaccharide chain, were removed with elastase to induce crystallization; residues 14–23 and presumably 86–88 …


The Refined Crystal Structure Of A Fully Active Semisynthetic Ribonuclease At 1.8 Å Resolution, Philip D. Martin, Marilynn S. Doscher, Brian Fp Edwards Nov 1987

The Refined Crystal Structure Of A Fully Active Semisynthetic Ribonuclease At 1.8 Å Resolution, Philip D. Martin, Marilynn S. Doscher, Brian Fp Edwards

Biochemistry and Molecular Biology Faculty Publications

A fully active, semisynthetic analog of bovine ribonuclease A, comprised of residues 1-118 of the molecule in a noncovalent complex with the synthetic peptide analog of residues 111-124, has been crystallized in space group P3(2)21 from a solution of 1.3 M ammonium sulfate and 3.0 M cesium chloride at pH 5.2. The crystallographic structure was determined by rotation and translation searches utilizing the coordinates for ribonuclease A reported by Wlodawer and Sjolin (Wlodawer, A., and Sjolin, L. (1983) Biochemistry 22, 2720-2728) and has been refined at 1.8-A resolution to an agreement factor of 0.204. Most of the structure of the …