scholarly journals MamO Is a Repurposed Serine Protease that Promotes Magnetite Biomineralization through Direct Transition Metal Binding in Magnetotactic Bacteria

PLoS Biology ◽  
2016 ◽  
Vol 14 (3) ◽  
pp. e1002402 ◽  
Author(s):  
David M. Hershey ◽  
Xuefeng Ren ◽  
Ryan A. Melnyk ◽  
Patrick J. Browne ◽  
Ertan Ozyamak ◽  
...  
Keyword(s):  
Transition Metal ◽  
Serine Protease ◽  
Metal Binding ◽  
Magnetotactic Bacteria ◽  
Direct Transition ◽  
Magnetite Biomineralization

scholarly journals Metal Free Amino-Oxidation of Electron Rich Alkenes Mediated by an Oxoammonium Salt

2020 ◽  
Author(s):  
Alexandra Millimaci ◽  
Rowan Meador ◽  
Sara Dampf ◽  
John D. Chisholm
Keyword(s):  
Transition Metal ◽  
Solvent Effects ◽  
Free Amino ◽  
Oxidation Products ◽  
Direct Transition ◽  
Metal Free ◽  
Mild Conditions ◽  
Relative Stereochemistry ◽  
Oxoammonium Salt

<div> <div> <div> <p>4-Acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate (Bobbitt’s salt) effectively activates electron rich alkenes and promotes the addition of anilines. This transformation provides a direct, transition metal free method for amino-oxidation of alkenes under mild conditions. The relative stereochemistry of the amino-oxidation is influenced by solvent effects, with both the syn and anti amino-oxidation products being accessible from identical starting materials. </p> </div> </div> </div>

scholarly journals A Compass To Boost Navigation: Cell Biology of Bacterial Magnetotaxis

2020 ◽  
Vol 202 (21) ◽  
Author(s):  
Frank D. Müller ◽  
Dirk Schüler ◽  
Daniel Pfeiffer
Keyword(s):  
Magnetic Field ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Magnetotactic Bacteria ◽  
Genetically Engineered ◽  
Model Organisms ◽  
Complex Cell ◽  
Magnetite Biomineralization ◽  
Directed Motility ◽  
The Impact

ABSTRACT Magnetotactic bacteria are aquatic or sediment-dwelling microorganisms able to take advantage of the Earth’s magnetic field for directed motility. The source of this amazing trait is magnetosomes, unique organelles used to synthesize single nanometer-sized crystals of magnetic iron minerals that are queued up to build an intracellular compass. Most of these microorganisms cannot be cultivated under controlled conditions, much less genetically engineered, with only few exceptions. However, two of the genetically amenable Magnetospirillum species have emerged as tractable model organisms to study magnetosome formation and magnetotaxis. Recently, much has been revealed about the process of magnetosome biogenesis and dedicated structures for magnetosome dynamics and positioning, which suggest an unexpected cellular intricacy of these organisms. In this minireview, we summarize new insights and place the molecular mechanisms of magnetosome formation in the context of the complex cell biology of Magnetospirillum spp. First, we provide an overview on magnetosome vesicle synthesis and magnetite biomineralization, followed by a discussion of the perceptions of dynamic organelle positioning and its biological implications, which highlight that magnetotactic bacteria have evolved sophisticated mechanisms to construct, incorporate, and inherit a unique navigational device. Finally, we discuss the impact of magnetotaxis on motility and its interconnection with chemotaxis, showing that magnetotactic bacteria are outstandingly adapted to lifestyle and habitat.

scholarly journals Structure and Metal Binding Properties of Chlamydia trachomatis YtgA

2019 ◽  
Vol 202 (1) ◽  
Author(s):  
Zhenyao Luo ◽  
Stephanie L. Neville ◽  
Rebecca Campbell ◽  
Jacqueline R. Morey ◽  
Shruti Menon ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Transition Metal ◽  
Metal Binding ◽  
Developed Countries ◽  
Biochemical Properties ◽  
Host Cells ◽  
Transmitted Infection ◽  
Content Type ◽  
Sexually Transmitted ◽  
Serious Disease

Chlamydia trachomatis is the most common bacterial sexually transmitted infection in developed countries, with an estimated global prevalence of 4.2% in the 15- to 49-year age group. Although infection is asymptomatic in more than 80% of infected women, about 10% of cases result in serious disease. Infection by C. trachomatis is dependent on the ability to acquire essential nutrients, such as the transition metal iron, from host cells. In this study, we show that iron is the most abundant transition metal in C. trachomatis and report the structural and biochemical properties of the iron-recruiting protein YtgA. Knowledge of the high-resolution structure of YtgA will provide a platform for future structure-based antimicrobial design approaches.

scholarly journals A Large Gene Cluster Encoding Several Magnetosome Proteins Is Conserved in Different Species of Magnetotactic Bacteria

2001 ◽  
Vol 67 (10) ◽  
pp. 4573-4582 ◽  
Author(s):  
Karen Grünberg ◽  
Cathrin Wawer ◽  
Bradley M. Tebo ◽  
Dirk Schüler
Keyword(s):  
Gene Cluster ◽  
Serine Proteases ◽  
Major Gene ◽  
Magnetotactic Bacteria ◽  
Large Gene ◽  
Specific Proteins ◽  
Magnetite Biomineralization ◽  
Cation Diffusion Facilitators ◽  
Tetratricopeptide Repeat Proteins ◽  
Genomic Regions

ABSTRACT In magnetotactic bacteria, a number of specific proteins are associated with the magnetosome membrane (MM) and may have a crucial role in magnetite biomineralization. We have cloned and sequenced the genes of several of these polypeptides in the magnetotactic bacterium Magnetospirillum gryphiswaldense that could be assigned to two different genomic regions. Except for mamA, none of these genes have been previously reported to be related to magnetosome formation. Homologous genes were found in the genome sequences ofM. magnetotacticum and magnetic coccus strain MC-1. The MM proteins identified display homology to tetratricopeptide repeat proteins (MamA), cation diffusion facilitators (MamB), and HtrA-like serine proteases (MamE) or bear no similarity to known proteins (MamC and MamD). A major gene cluster containing several magnetosome genes (including mamA and mamB) was found to be conserved in all three of the strains investigated. ThemamAB cluster also contains additional genes that have no known homologs in any nonmagnetic organism, suggesting a specific role in magnetosome formation.

Transition-metal binding site of bleomycin. A synthetic analog capable of binding iron(II) to yield an oxygen-sensitive complex

1981 ◽  
Vol 103 (23) ◽  
pp. 6986-6988 ◽  
Author(s):  
Masami Otsuka ◽  
Makoto Yoshida ◽  
Susumu Kobayashi ◽  
Masaji Ohno ◽  
Yukio Sugiura ◽  
...  
Keyword(s):  
Transition Metal ◽  
Binding Site ◽  
Metal Binding ◽  
Synthetic Analog ◽  
Metal Binding Site ◽  
Oxygen Sensitive
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