请输入您要查询的百科知识：

　

词条 Cation diffusion facilitator
释义

  1. The Cation Diffusion Facilitator (CDF) Family

      Phylogeny    Structure    Transport Reaction  

  2. See also

  3. References

{{Infobox protein family
| Symbol = Cation_efflux
| Name = Cation_efflux
| image =
| width =
| caption = structural basis for the autoregulation of the zinc transporter yiip
| Pfam = PF01545
| Pfam_clan = CL0184
| InterPro = IPR002524
| SMART =
| PROSITE =
| MEROPS =
| SCOP =
| TCDB = 2.A.4
| OPM family = 183
| OPM protein = 3h90
| CAZy =
| CDD =
}}Cation diffusion facilitators (CDFs) are transmembrane proteins that provide tolerance of cells to divalent metal ions, such as cadmium, zinc, and cobalt. These proteins are considered to be efflux pumps that remove these divalent metal ions from cells.[1][2] However, some members of the CDF superfamily are implicated in ion uptake.[3] All members of the CDF family possess six putative transmembrane spanners with strongest conservation in the four N-terminal spanners.[4] The Cation Diffusion Facilitator (CDF) Superfamily includes the following families:[4][4]
  • 1.A.52 - The Ca2+ Release-activated Ca2+ (CRAC) Channel (CRAC-C) Family
  • 2.A.4 - The Cation Diffusion Facilitator (CDF) Family
  • 2.A.19 - The Ca2+:Cation Antiporter (CaCA) Family
  • 2.A.103 - The Bacterial Murein Precursor Exporter (MPE) Family

The Cation Diffusion Facilitator (CDF) Family

The CDF family (TC# 2.A.4) is a ubiquitous family, members of which are found in bacteria, archaea and eukaryotes.[5] They transport heavy metal ions, such as cadmium, zinc, cobalt, nickel, copper and mercuric ions. There are 9 mammalian paralogues, ZnT1 - 8 and 10.[6] Most proteins from the family have six transmembrane helices, but MSC2 of S. cerevisiae) and Znt5 and hZTL1 of H. sapiens have 15 and 12 predicted TMSs, respectively.[7] These proteins exhibit an unusual degree of sequence divergence and size variation (300-750 residues). Eukaryotic proteins exhibit differences in cell localization. Some catalyze heavy metal uptake from the cytoplasm into various intracellular eukaryotic organelles (ZnT2-7) while others (ZnT1) catalyze efflux from the cytoplasm across the plasma membrane into the extracellular medium. Thus, some are found in plasma membranes while others are in organellar membranes such as vacuoles of plants and yeast and the golgi of animals.[8][9][10] They catalyze cation:proton antiport, have a single essential zinc-binding site within the transmembrane domains of each monomer within the dimer, and have a binuclear zinc-sensing and binding site in the cytoplasmic C-terminal region.[11] A representative list of proteins belonging to the CDF family can be found in the Transporter Classification Database.

Phylogeny

Prokaryotic and eukaryotic proteins cluster separately but may function with the same polarity by similar mechanisms. These proteins are secondary carriers which utilize the proton motive force (pmf) and function by H+ antiport (for metal efflux). One member, CzcD of Bacillus subtilis (TC# 2.A.4.1.3) , has been shown to exchange the divalent cation (Zn2+ or Cd2+ ) for two monovalent cations (K+ and H+ ) in an electroneutral process energized by the transmembrane pH gradient.[12] Another, ZitB of E. coli (TC #2.A.4.1.4), has been reconstituted in proteoliposomes and studied kinetically.[13] It appears to function by simple Me2+:H+ antiport with a 1:1 stoichiometry.

Montanini et al. (2007) have conducted phylogenetic analysis of CDF family members. Their analysis revealed three major and two minor phylogenetic groups. They suggest that the three major groups segregated according to metal ion specificity:[14]

  1. Mn2+
  2. Fe2+ and Zn2+ as well as other metal ions
  3. Zn2+ plus other metals, but not Iron.

Structure

X-ray structure of YiiP of E. coli represents a homodimer.[15][16]

Coudray et al. (2013) used cryoelectron microscopy to determine a 13 Å resolution structure of a YiiP homolog from Shewanella oneidensis within a lipid bilayer in the absence of Zn2+. Starting from the x-ray structure in the presence of Zn2+, they used molecular dynamic flexible fitting to build a model. Comparison of the structures suggested a conformational change that involves pivoting of a transmembrane, four-helix bundle (M1, M2, M4, and M5) relative to the M3-M6 helix pair. Although accessibility of transport sites in the x-ray model indicates that it represents an outward-facing state, their model was consistent with an inward-facing state, suggesting that the conformational change is relevant to the alternating access mechanism for transport. They speculated that the dimer may coordinate rearrangement of the transmembrane helices.[17]

Involved in metal tolerance/resistance by efflux, most CDF proteins share a two-modular architecture consisting of a transmembrane domain (TMD) and a C-terminal domain (CTD) that protrudes into the cytoplasm. A Zn2+ and Cd2+ CDF transporter from the marine bacterium, Maricaulis maris, that does not possess the CTD is a member of a new, CTD-lacking subfamily of CDFs.

Transport Reaction

The generalized transport reaction for CDF family members is:

Me2+ (in) H+ (out) ± K+ (out) → Me2+ (out) H+ (in) ± K+ (in).

See also

  • Integral membrane protein
  • Ion channel
  • Transporter Classification Database
  • Protein superfamily
  • Protein family

References

1. ^{{cite journal |vauthors=Xiong A, Jayaswal RK | title = Molecular characterization of a chromosomal determinant conferring resistance to zinc and cobalt ions in Staphylococcus aureus | journal = J. Bacteriol. | volume = 180 | issue = 16 | pages = 4024–9 |date=August 1998 | pmid = 9696746 | pmc = 107394 | doi = | url = }}
2. ^{{cite journal |vauthors=Kunito T, Kusano T, Oyaizu H, Senoo K, Kanazawa S, Matsumoto S | title = Cloning and sequence analysis of czc genes in Alcaligenes sp. strain CT14 | journal = Biosci. Biotechnol. Biochem. | volume = 60 | issue = 4 | pages = 699–704 |date=April 1996 | pmid = 8829543 | doi = 10.1271/bbb.60.699| url = }}
3. ^{{cite journal |vauthors=Conklin DS, McMaster JA, Culbertson MR, Kung C | title = COT1, a gene involved in cobalt accumulation in Saccharomyces cerevisiae | journal = Mol. Cell. Biol. | volume = 12 | issue = 9 | pages = 3678–88 |date=September 1992 | pmid = 1508175 | pmc = 360222 | doi = | url = }}
4. ^{{Cite web|url = http://www.tcdb.org/superfamily.php?id=29|title = Cation Diffusion Facilitator (CDF) Superfamily|date = |access-date = |website = Transporter Classification Database|publisher = |last = Saier|first = MH Jr}}
5. ^1 2 {{Cite journal|title = A novel family of ubiquitous heavy metal ion transport proteins.|last = Paulson|first = IT|date = 1997|journal = Journal of Membrane Biology|doi = |pmid = 9075641|last2 = Saier|first2 = MH Jr.|issue = 2|volume = 156|pages = 99–103}}
6. ^{{Cite journal|title = Mammalian zinc transport, trafficking, and signals|journal = The Journal of Biological Chemistry|date = 2006-08-25|issn = 0021-9258|pmid = 16793761|pages = 24085–24089|volume = 281|issue = 34|doi = 10.1074/jbc.R600011200|first = Robert J.|last = Cousins|first2 = Juan P.|last2 = Liuzzi|first3 = Louis A.|last3 = Lichten}}
7. ^{{Cite journal|title = A novel zinc-regulated human zinc transporter, hZTL1, is localized to the enterocyte apical membrane|journal = The Journal of Biological Chemistry|date = 2002-06-21|issn = 0021-9258|pmid = 11937503|pages = 22789–22797|volume = 277|issue = 25|doi = 10.1074/jbc.M200577200|first = Ruth A.|last = Cragg|first2 = Graham R.|last2 = Christie|first3 = Siôn R.|last3 = Phillips|first4 = Rachel M.|last4 = Russi|first5 = Sébastien|last5 = Küry|first6 = John C.|last6 = Mathers|first7 = Peter M.|last7 = Taylor|first8 = Dianne|last8 = Ford}}
8. ^{{Cite journal|title = Thermodynamic studies of the mechanism of metal binding to the Escherichia coli zinc transporter YiiP|journal = The Journal of Biological Chemistry|date = 2004-04-23|issn = 0021-9258|pmid = 14960568|pages = 17173–17180|volume = 279|issue = 17|doi = 10.1074/jbc.M400208200|first = Yang|last = Chao|first2 = Dax|last2 = Fu}}
9. ^{{Cite journal|title = New developments in the understanding of the cation diffusion facilitator family|journal = Journal of Industrial Microbiology & Biotechnology|date = 2005-06-01|issn = 1367-5435|pmid = 15889311|pages = 215–226|volume = 32|issue = 6|doi = 10.1007/s10295-005-0224-3|first = Christopher J.|last = Haney|first2 = Gregor|last2 = Grass|first3 = Sylvia|last3 = Franke|first4 = Christopher|last4 = Rensing}}
10. ^{{Cite journal|title = Induction of the ZRC1 metal tolerance gene in zinc-limited yeast confers resistance to zinc shock|journal = The Journal of Biological Chemistry|date = 2003-04-25|issn = 0021-9258|pmid = 12556516|pages = 15065–15072|volume = 278|issue = 17|doi = 10.1074/jbc.M300568200|first = Colin W.|last = MacDiarmid|first2 = Mark A.|last2 = Milanick|first3 = David J.|last3 = Eide}}
11. ^{{Cite journal|title = Molecular architecture and function of ZnT transporters|journal = Current Topics in Membranes|date = 2012-01-01|issn = 1063-5823|pmid = 23046652|pages = 199–220|volume = 69|doi = 10.1016/B978-0-12-394390-3.00008-2|first = Taiho|last = Kambe}}
12. ^{{Cite journal|title = An antiport mechanism for a member of the cation diffusion facilitator family: divalent cations efflux in exchange for K+ and H+|journal = Molecular Microbiology|date = 2002-07-01|issn = 0950-382X|pmid = 12100555|pages = 145–153|volume = 45|issue = 1|first = Arthur A.|last = Guffanti|first2 = Yi|last2 = Wei|first3 = Sacha V.|last3 = Rood|first4 = Terry A.|last4 = Krulwich|doi=10.1046/j.1365-2958.2002.02998.x}}
13. ^{{Cite journal|title = Kinetic study of the antiport mechanism of an Escherichia coli zinc transporter, ZitB|journal = The Journal of Biological Chemistry|date = 2004-03-26|issn = 0021-9258|pmid = 14715669|pages = 12043–12050|volume = 279|issue = 13|doi = 10.1074/jbc.M313510200|first = Yang|last = Chao|first2 = Dax|last2 = Fu}}
14. ^{{Cite journal|title = Phylogenetic and functional analysis of the Cation Diffusion Facilitator (CDF) family: improved signature and prediction of substrate specificity|journal = BMC Genomics|date = 2007-01-01|issn = 1471-2164|pmc = 1868760|pmid = 17448255|pages = 107|volume = 8|doi = 10.1186/1471-2164-8-107|first = Barbara|last = Montanini|first2 = Damien|last2 = Blaudez|first3 = Sylvain|last3 = Jeandroz|first4 = Dale|last4 = Sanders|first5 = Michel|last5 = Chalot}}
15. ^{{Cite journal|title = Oligomeric state of the Escherichia coli metal transporter YiiP|journal = The Journal of Biological Chemistry|date = 2004-09-17|issn = 0021-9258|pmid = 15258151|pages = 39251–39259|volume = 279|issue = 38|doi = 10.1074/jbc.M407044200|first = Yinan|last = Wei|first2 = Huilin|last2 = Li|first3 = Dax|last3 = Fu}}
16. ^{{Cite journal|title = Structure of the zinc transporter YiiP|journal = Science|date = 2007-09-21|issn = 1095-9203|pmid = 17717154|pages = 1746–1748|volume = 317|issue = 5845|doi = 10.1126/science.1143748|first = Min|last = Lu|first2 = Dax|last2 = Fu}}
17. ^{{Cite journal|title = Inward-facing conformation of the zinc transporter YiiP revealed by cryoelectron microscopy|journal = Proceedings of the National Academy of Sciences of the United States of America|date = 2013-02-05|issn = 1091-6490|pmc = 3568326|pmid = 23341604|pages = 2140–2145|volume = 110|issue = 6|doi = 10.1073/pnas.1215455110|first = Nicolas|last = Coudray|first2 = Salvatore|last2 = Valvo|first3 = Minghui|last3 = Hu|first4 = Ralph|last4 = Lasala|first5 = Changki|last5 = Kim|first6 = Martin|last6 = Vink|first7 = Ming|last7 = Zhou|first8 = Davide|last8 = Provasi|first9 = Marta|last9 = Filizola}}
{{InterPro content|IPR002524}}{{Portal bar|Molecular and Cellular Biology|border=no}}

7 : Biology|Protein families|Membrane proteins|Transmembrane proteins|Transmembrane transporters|Transport proteins|Integral membrane proteins
随便看

　

开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。

　

Copyright © 2023 OENC.NET All Rights Reserved
京ICP备2021023879号 更新时间：2024/9/23 11:28:48