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The LysE Superfamily of Transport Proteins Involved in Cell Physiology and Pathogenesis.

Tsu BV, Saier MH - PLoS ONE (2015)

Bottom Line: Internal repeats and conserved motifs were identified, and multiple alignments, phylogenetic trees and average hydropathy, amphipathicity and similarity plots provided evidence that all members of the superfamily derived from a single common 3-TMS precursor peptide via intragenic duplication.Their common origin implies that they share common structural, mechanistic and functional attributes.The transporters of this superfamily play important roles in ionic homeostasis, cell envelope assembly, and protection from excessive cytoplasmic heavy metal/metabolite concentrations.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, United States of America.

ABSTRACT
The LysE superfamily consists of transmembrane transport proteins that catalyze export of amino acids, lipids and heavy metal ions. Statistical means were used to show that it includes newly identified families including transporters specific for (1) tellurium, (2) iron/lead, (3) manganese, (4) calcium, (5) nickel/cobalt, (6) amino acids, and (7) peptidoglycolipids as well as (8) one family of transmembrane electron carriers. Internal repeats and conserved motifs were identified, and multiple alignments, phylogenetic trees and average hydropathy, amphipathicity and similarity plots provided evidence that all members of the superfamily derived from a single common 3-TMS precursor peptide via intragenic duplication. Their common origin implies that they share common structural, mechanistic and functional attributes. The transporters of this superfamily play important roles in ionic homeostasis, cell envelope assembly, and protection from excessive cytoplasmic heavy metal/metabolite concentrations. They thus influence the physiology and pathogenesis of numerous microbes, being potential targets of drug action.

No MeSH data available.


Related in: MedlinePlus

Schematic diagrams depicting motifs and highly conserved residues within and between the LysE (LE) and TerC (TC) families.A) Schematic diagram of LysE proteins. B) Schematic diagram of TerC proteins. C) Graphical representation of the shared motifs depicted in Part A and Part B. D) Symbol Legend.
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pone.0137184.g005: Schematic diagrams depicting motifs and highly conserved residues within and between the LysE (LE) and TerC (TC) families.A) Schematic diagram of LysE proteins. B) Schematic diagram of TerC proteins. C) Graphical representation of the shared motifs depicted in Part A and Part B. D) Symbol Legend.

Mentions: Previous mutation studies on the LysE protein in Corynebacterium glutamicum demonstrated the importance of highly conserved residues in the second and fourth hydrophobic segments of the protein [46]. A highly conserved aspartic acid (D) is present in the second hydrophobic segment of LysE, and its negative charge is essential for translocation of L-lysine. In addition, mutations to the fully conserved asparaginyl (N) and prolyl (P) in the fourth hydrophobic segment reduce export function dramatically. The prolyl residue in particular holds importance for three-dimensional structures of the carrier, and any changes in the neighboring asparaginyl residue would introduce steric hindrance. A fully conserved aspartic acid (D) is also present in the fourth hydrophobic segment, and has been proposed to bind the L-lysine substrate. Change of this aspartic acid (D) to a lysyl (K) residue resulted in an inactive protein. In the present study, motifs identified using the MEME/MAST Suite (www.meme.nbcr.net/meme/) for the different families were compared with one another (Figs 3, 4, 5 and 6, Table 5) [16]. Here we report strongly conserved residues within and between families.


The LysE Superfamily of Transport Proteins Involved in Cell Physiology and Pathogenesis.

Tsu BV, Saier MH - PLoS ONE (2015)

Schematic diagrams depicting motifs and highly conserved residues within and between the LysE (LE) and TerC (TC) families.A) Schematic diagram of LysE proteins. B) Schematic diagram of TerC proteins. C) Graphical representation of the shared motifs depicted in Part A and Part B. D) Symbol Legend.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608589&req=5

pone.0137184.g005: Schematic diagrams depicting motifs and highly conserved residues within and between the LysE (LE) and TerC (TC) families.A) Schematic diagram of LysE proteins. B) Schematic diagram of TerC proteins. C) Graphical representation of the shared motifs depicted in Part A and Part B. D) Symbol Legend.
Mentions: Previous mutation studies on the LysE protein in Corynebacterium glutamicum demonstrated the importance of highly conserved residues in the second and fourth hydrophobic segments of the protein [46]. A highly conserved aspartic acid (D) is present in the second hydrophobic segment of LysE, and its negative charge is essential for translocation of L-lysine. In addition, mutations to the fully conserved asparaginyl (N) and prolyl (P) in the fourth hydrophobic segment reduce export function dramatically. The prolyl residue in particular holds importance for three-dimensional structures of the carrier, and any changes in the neighboring asparaginyl residue would introduce steric hindrance. A fully conserved aspartic acid (D) is also present in the fourth hydrophobic segment, and has been proposed to bind the L-lysine substrate. Change of this aspartic acid (D) to a lysyl (K) residue resulted in an inactive protein. In the present study, motifs identified using the MEME/MAST Suite (www.meme.nbcr.net/meme/) for the different families were compared with one another (Figs 3, 4, 5 and 6, Table 5) [16]. Here we report strongly conserved residues within and between families.

Bottom Line: Internal repeats and conserved motifs were identified, and multiple alignments, phylogenetic trees and average hydropathy, amphipathicity and similarity plots provided evidence that all members of the superfamily derived from a single common 3-TMS precursor peptide via intragenic duplication.Their common origin implies that they share common structural, mechanistic and functional attributes.The transporters of this superfamily play important roles in ionic homeostasis, cell envelope assembly, and protection from excessive cytoplasmic heavy metal/metabolite concentrations.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, United States of America.

ABSTRACT
The LysE superfamily consists of transmembrane transport proteins that catalyze export of amino acids, lipids and heavy metal ions. Statistical means were used to show that it includes newly identified families including transporters specific for (1) tellurium, (2) iron/lead, (3) manganese, (4) calcium, (5) nickel/cobalt, (6) amino acids, and (7) peptidoglycolipids as well as (8) one family of transmembrane electron carriers. Internal repeats and conserved motifs were identified, and multiple alignments, phylogenetic trees and average hydropathy, amphipathicity and similarity plots provided evidence that all members of the superfamily derived from a single common 3-TMS precursor peptide via intragenic duplication. Their common origin implies that they share common structural, mechanistic and functional attributes. The transporters of this superfamily play important roles in ionic homeostasis, cell envelope assembly, and protection from excessive cytoplasmic heavy metal/metabolite concentrations. They thus influence the physiology and pathogenesis of numerous microbes, being potential targets of drug action.

No MeSH data available.


Related in: MedlinePlus