scholarly journals The cation diffusion facilitator proteins MamB and MamM of Magnetospirillum gryphiswaldense have distinct and complex functions, and are involved in magnetite biomineralization and magnetosome membrane assembly

2011 ◽  
Vol 82 (4) ◽  
pp. 818-835 ◽  
Author(s):  
René Uebe ◽  
Katja Junge ◽  
Verena Henn ◽  
Gabriele Poxleitner ◽  
Emanuel Katzmann ◽  
...  
Keyword(s):  
Cation Diffusion ◽  
Cation Diffusion Facilitator ◽  
Magnetospirillum Gryphiswaldense ◽  
Membrane Assembly ◽  
Complex Functions ◽  
Magnetite Biomineralization

scholarly journals Structural basis for the alternating access mechanism of the cation diffusion facilitator YiiP

2018 ◽  
Vol 115 (12) ◽  
pp. 3042-3047 ◽  
Author(s):  
Maria Luisa Lopez-Redondo ◽  
Nicolas Coudray ◽  
Zhening Zhang ◽  
John Alexopoulos ◽  
David L. Stokes
Keyword(s):  
Large Scale ◽  
Structural Basis ◽  
Membrane Domains ◽  
Cation Diffusion ◽  
Cation Diffusion Facilitator ◽  
X Ray ◽  
Bacterial Membranes ◽  
Helix Bundle ◽  
Four Helix Bundle ◽  
Alternating Access

YiiP is a dimeric antiporter from the cation diffusion facilitator family that uses the proton motive force to transport Zn2+ across bacterial membranes. Previous work defined the atomic structure of an outward-facing conformation, the location of several Zn2+ binding sites, and hydrophobic residues that appear to control access to the transport sites from the cytoplasm. A low-resolution cryo-EM structure revealed changes within the membrane domain that were associated with the alternating access mechanism for transport. In the current work, the resolution of this cryo-EM structure has been extended to 4.1 Å. Comparison with the X-ray structure defines the differences between inward-facing and outward-facing conformations at an atomic level. These differences include rocking and twisting of a four-helix bundle that harbors the Zn2+ transport site and controls its accessibility within each monomer. As previously noted, membrane domains are closely associated in the dimeric structure from cryo-EM but dramatically splayed apart in the X-ray structure. Cysteine crosslinking was used to constrain these membrane domains and to show that this large-scale splaying was not necessary for transport activity. Furthermore, dimer stability was not compromised by mutagenesis of elements in the cytoplasmic domain, suggesting that the extensive interface between membrane domains is a strong determinant of dimerization. As with other secondary transporters, this interface could provide a stable scaffold for movements of the four-helix bundle that confers alternating access of these ions to opposite sides of the membrane.

scholarly journals A secretory pathway-localized cation diffusion facilitator confers plant manganese tolerance

2007 ◽  
Vol 104 (20) ◽  
pp. 8532-8537 ◽  
Author(s):  
E. Peiter ◽  
B. Montanini ◽  
A. Gobert ◽  
P. Pedas ◽  
S. Husted ◽  
...  
Keyword(s):  
Secretory Pathway ◽  
Cation Diffusion ◽  
Cation Diffusion Facilitator ◽  
Manganese Tolerance

scholarly journals Multi-genomic analysis of the Cation Diffusion Facilitator transporters from algae

2019 ◽  
Author(s):  
Aniefon Ibuot ◽  
Andrew P. Dean ◽  
Jon K. Pittman
Keyword(s):  
Metal Ion ◽  
Transmembrane Domain ◽  
Higher Plants ◽  
Phylogenetic Analyses ◽  
Algal Species ◽  
Genomic Analysis ◽  
Transport Processes ◽  
Transport Function ◽  
Cation Diffusion ◽  
Cation Diffusion Facilitator

AbstractMetal transport processes are relatively poorly understood in algae in comparison to higher plants and other eukaryotes. A screen of genomes from 33 taxonomically diverse algal species was conducted to identify members of the Cation Diffusion Facilitator (CDF) family of metal ion transporter. All algal genomes contained at least one CDF gene with four species having >10 CDF genes (median of 5 genes per genome), further confirming that this is a ubiquitous gene family. Phylogenetic analysis suggested a CDF gene organisation of five groups, which includes Zn-CDF, Fe/Zn-CDF and Mn-CDF groups, consistent with previous phylogenetic analyses, and two functionally undefined groups. One of these undefined groups was algal specific although excluded chlorophyte and rhodophyte sequences. The majority of sequences (22 out of 26 sequences) from this group had a putative ion binding site motif within transmembrane domain 2 and 5 that was distinct from other CDF proteins, such that alanine or serine replaced the conserved histidine residue. The phylogenetic grouping was supported by sequence cluster analysis. Yeast heterologous expression of CDF proteins from Chlamydomonas reinhardtii indicated Zn2+ and Co2+ transport function by CrMTP1, and Mn2+ transport function by CrMTP2, CrMTP3 and CrMTP4, which validated the phylogenetic prediction. However, the Mn-CDF protein CrMTP3 was also able to provide zinc and cobalt tolerance to the Zn- and Co-sensitive zrc1cot1 yeast strain. There is wide diversity of CDF transporters within the algae lineage, and some of these genes may be attractive targets for future applications of metal content engineering in plants or microorganisms.

scholarly journals The Cation Diffusion Facilitator Family Protein EmfA Confers Resistance to Manganese Toxicity in Brucella abortus 2308 and Is an Essential Virulence Determinant in Mice

2019 ◽  
Vol 202 (1) ◽  
Author(s):  
Matthew J. Johnsrude ◽  
Joshua E. Pitzer ◽  
Daniel W. Martin ◽  
R. Martin Roop
Keyword(s):  
Brucella Abortus ◽  
Manganese Toxicity ◽  
Cation Diffusion ◽  
Cation Diffusion Facilitator ◽  
Mn Toxicity ◽  
Virulence Determinant ◽  
Family Protein ◽  
Cellular Components ◽  
Cation Diffusion Facilitator Family

Mn nutrition is essential for the basic physiology and virulence of Brucella strains. The results of the study presented here demonstrate that the cation diffusion facilitator (CDF)-type metal exporter EmfA plays critical roles in maintaining Mn homeostasis and preventing Mn toxicity in Brucella and is an essential virulence determinant for these bacteria. EmfA and other cellular components involved in Mn homeostasis represent attractive targets for the development of improved vaccines and chemotherapeutic strategies for preventing and treating brucellosis in humans and animals.

Crystal structure of the cytosolic domain of the cation diffusion facilitator family protein

2009 ◽  
Vol 76 (3) ◽  
pp. 768-771 ◽  
Author(s):  
Takashi Higuchi ◽  
Motoyuki Hattori ◽  
Yoshiki Tanaka ◽  
Ryuichiro Ishitani ◽  
Osamu Nureki
Keyword(s):  
Crystal Structure ◽  
Cation Diffusion ◽  
Cation Diffusion Facilitator ◽  
Family Protein ◽  
Cytosolic Domain ◽  
Cation Diffusion Facilitator Family

scholarly journals Functional Determinants of Metal Ion Transport and Selectivity in Paralogous Cation Diffusion Facilitator Transporters CzcD and MntE in Streptococcus pneumoniae

2016 ◽  
Vol 198 (7) ◽  
pp. 1066-1076 ◽  
Author(s):  
Julia E. Martin ◽  
David P. Giedroc
Keyword(s):  
Streptococcus Pneumoniae ◽  
Metal Ion ◽  
Transmembrane Domain ◽  
Divalent Metal ◽  
Cation Diffusion ◽  
Metal Specificity ◽  
Cation Diffusion Facilitator ◽  
Content Type ◽  
Metal Selectivity ◽  
A Site

ABSTRACTCation diffusion facilitators (CDFs) are a large family of divalent metal transporters that collectively possess broad metal specificity and contribute to intracellular metal homeostasis and virulence in bacterial pathogens.Streptococcus pneumoniaeexpresses two homologous CDF efflux transporters, MntE and CzcD. Cells lackingmntEorczcDare sensitive to manganese (Mn) or zinc (Zn) toxicity, respectively, and specifically accumulate Mn or Zn, respectively, thus suggesting that MntE selectively transports Mn, while CzcD transports Zn. Here, we probe the origin of this metal specificity using a phenotypic growth analysis of pneumococcal variants. Structural homology toEscherichia coliYiiP predicts that both MntE and CzcD are dimeric and each protomer harbors four pairs of conserved metal-binding sites, termed the A site, the B site, and the C1/C2 binuclear site. We find that single amino acid mutations within both the transmembrane domain A site and the B site in both CDFs result in a cellular metal sensitivity similar to that of the corresponding null mutants. However, multiple mutations in the predicted cytoplasmic C1/C2 cluster of MntE have no impact on cellular Mn resistance, in contrast to the analogous substitutions in CzcD, which do have on impact on cellular Zn resistance. Deletion of the MntE-specific C-terminal tail, present only in Mn-specific bacterial CDFs, resulted in only a modest growth phenotype. Further analysis of MntE-CzcD functional chimeric transporters showed that Asn and Asp in theND-DD A-site motif of MntE and the most N-terminal His in theHD-HD site A of CzcD (the specified amino acids are underlined) play key roles in transporter metal selectivity.IMPORTANCECation diffusion facilitator (CDF) proteins are divalent metal ion transporters that are conserved in organisms ranging from bacteria to humans and that play important roles in cellular physiology, from metal homeostasis and resistance to type I diabetes in vertebrates. The respiratory pathogenStreptococcus pneumoniaeexpresses two metal CDF transporters, CzcD and MntE. How CDFs achieve metal selectivity is unclear. We show here that CzcD and MntE are true paralogs, as CzcD transports zinc, while MntE selectively transports manganese. Through the use of an extensive collection of pneumococcal variants, we show that a primary determinant for metal selectivity is the A site within the transmembrane domain. This extends our understanding of how CDFs discriminate among transition metals.

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