| 词条 | SMC protein | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
SMC proteins represent a large family of ATPases that participate in many aspects of higher-order chromosome organization and dynamics.[1][2][3] SMC stands for Structural Maintenance of Chromosomes. ClassificationEukaryotic SMCsEukaryotes have at least six SMC proteins in individual organisms, and they form three distinct heterodimers with specialized functions:
Each complex contains a distinct set of non-SMC regulatory subunits. Some organisms have variants of SMC proteins. For instance, mammals have a meiosis-specific variant of SMC1, known as SMC1β.[10] The nematode Caenorhabditis elegans has an SMC4-variant that has a specialized role in dosage compensation.[11]
Prokaryotic SMCsSMC proteins are conserved from bacteria to humans. Most bacteria have a single SMC protein in individual species that forms a homodimer.[12] In a subclass of Gram-negative bacteria including Escherichia coli, a distantly related protein known as MukB plays an equivalent role.[13] Molecular structurePrimary structureSMC proteins are 1,000-1,500 amino-acid long. They have a modular structure that is composed of the following domains:
Secondary and tertiary structureSMC dimers form a V-shaped molecule with two long coiled-coil arms.[14][15] To make such a unique structure, an SMC protomer is self-folded through anti-parallel coiled-coil interactions, forming a rod-shaped molecule. At one end of the molecule, the N-terminal and C-terminal domains together form an ATP-binding domain. The other end is called a hinge domain. Two protomers then dimerize through their hinge domains and assemble a V-shaped dimer.[16][17] The length of the coiled-coil arms is ~50 nm long. Such long "antiparallel" coiled-coils are very rare, and found only among SMC proteins (and its relatives such as Rad50). The ATP-binding domain of SMC proteins is structurally related to that of ABC transporters, a large family of transmembrane proteins that actively transport small molecules across cellular membranes. It is thought that the cycle of ATP binding and hydrolysis modulates the cycle of closing and opening of the V-shaped molecule, but the detailed mechanisms of action of SMC proteins remain to be determined. GenesThe following human genes encode SMC proteins:
See also{{Commons category|SMC proteins}}
References1. ^{{cite journal |vauthors=Losada A, Hirano T |title=Dynamic molecular linkers of the genome: the first decade of SMC proteins |journal= Genes Dev |volume= 19 |issue= 11 |pages= 1269–1287 |year= 2005| doi = 10.1101/gad.1320505 |pmid= 15937217}} {{Nucleus}}{{Acid anhydride hydrolases}}{{Enzymes}}{{Portal bar|Molecular and Cellular Biology|border=no}}2. ^{{cite journal |vauthors=Nasmyth K, Haering CH | title = The structure and function of SMC and kleisin complexes.| journal = Annu. Rev. Biochem. | volume = 74 | pages = 595–648| year = 2005 | pmid = 15952899 | doi=10.1146/annurev.biochem.74.082803.133219}} 3. ^{{cite journal |vauthors=Huang CE, Milutinovich M, Koshland D |title=Rings, bracelet or snaps: fashionable alternatives for Smc complexes|journal= Philos Trans R Soc Lond B Biol Sci |volume= 360 |issue= 1455 |pages= 537–42 |year= 2005| doi = 10.1098/rstb.2004.1609 |pmid= 15897179 |pmc=1569475}} 4. ^{{cite journal |vauthors=Michaelis C, Ciosk R, Nasmyth K | title = Cohesins: chromosomal proteins that prevent premature separation of sister chromatids | journal =Cell| volume = 91 | issue = 1 | pages = 35–45| year = 1997 | pmid = 9335333 | doi=10.1016/S0092-8674(01)80007-6}} 5. ^{{cite journal |vauthors=Guacci V, Koshland D, Strunnikov A | title = A direct link between sister chromatid cohesion and chromosome condensation revealed through the analysis of MCD1 in S. cerevisiae | journal = Cell | volume = 91 | issue = 1 | pages = 47–57| year = 1998 | pmid = 9335334 | pmc=2670185 | doi=10.1016/S0092-8674(01)80008-8}} 6. ^{{cite journal |vauthors=Losada A, Hirano M, Hirano T | title = Identification of Xenopus SMC protein complexes required for sister chromatid cohesion | journal = Genes Dev. | volume = 12 | issue = 13 | pages = 1986–1997| year = 1998 | pmid = 9649503 | pmc = 316973 | doi=10.1101/gad.12.13.1986}} 7. ^{{cite journal |vauthors=Hirano T, Kobayashi R, Hirano M | title = Condensins, chromosome condensation complex containing XCAP-C, XCAP-E and a Xenopus homolog of the Drosophila Barren protein | journal = Cell | volume = 89 | issue = 4 | pages = 511–21 | year = 1997 | pmid = 9160743 | doi=10.1016/S0092-8674(00)80233-0}} 8. ^{{cite journal |vauthors=Ono T, Losada A, Hirano M, Myers MP, Neuwald AF, Hirano T | title = Differential contributions of condensin I and condensin II to mitotic chromosome architecture in vertebrate cells | journal = Cell| volume = 115 | issue = 1 | pages = 109–21 | year = 2003 | pmid = 14532007 | doi=10.1016/S0092-8674(03)00724-4}} 9. ^{{cite journal |vauthors=Fousteri MI, Lehmann AR | title = A novel SMC protein complex in Schizosaccharomyces pombe contains the Rad18 DNA repair protein | journal = EMBO J. | volume =19 | issue = 7 | pages = 1691–1702 | year = 2000 | pmid = 10747036 | pmc = 310237 | doi=10.1093/emboj/19.7.1691}} 10. ^{{cite journal |vauthors=Revenkova E, Eijpe M, Heyting C, Gross B, Jessberger R | title = Novel meiosis-specific isoform of mammalian SMC1 | journal = Mol. Cell. Biol. | volume = 21 | issue = 20 | pages = 6984–6998| year = 2001 | pmid = 11564881 | doi=10.1128/MCB.21.20.6984-6998.2001 | pmc=99874}} 11. ^{{cite journal |vauthors=Chuang PT, Albertson DG, Meyer BJ | title = DPY-27:a chromosome condensation protein homolog that regulates C. elegans dosage compensation through association with the X chromosome | journal = Cell | volume = 79 | issue = 3 | pages = 459–474| year = 1994 | pmid = 7954812 | doi=10.1016/0092-8674(94)90255-0}} 12. ^{{cite journal |vauthors=Britton RA, Lin DC, Grossman AD | title = Characterization of a prokaryotic SMC protein involved in chromosome partitioning| journal = Genes Dev.| volume = 12 | issue = 9 | pages = 1254–1259| year = 1998 | pmid = 9573042 | pmc = 316777| doi=10.1101/gad.12.9.1254}} 13. ^{{cite journal |vauthors=Niki H, Jaffé A, Imamura R, Ogura T, Hiraga S | title = The new gene mukB codes for a 177 kd protein with coiled-coil domains involved in chromosome partitioning of E. coli| journal = EMBO J.| volume = 10 | issue = 1 | pages = 183–193| year = 1991 | pmid = 1989883| pmc = 452628| doi = 10.1002/j.1460-2075.1991.tb07935.x}} 14. ^{{cite journal |vauthors=Melby TE, Ciampaglio CN, Briscoe G, Erickson HP | title = The symmetrical structure of structural maintenance of chromosomes (SMC) and MukB proteins: long, antiparallel coiled coils, folded at a flexible hinge| journal = J. Cell Biol.| volume = 142 | issue = 6 | pages = 1595–1604 | year = 1998 | pmid = 9744887 | pmc = 2141774| doi=10.1083/jcb.142.6.1595}} 15. ^{{cite journal |vauthors=Anderson DE, Losada A, Erickson HP, Hirano T | title = Condensin and cohesin display different arm conformations with characteristic hinge angles| journal = J. Cell Biol.| volume = 156 | issue = 6 | pages = 419–424 | year = 2002 | pmid = 11815634 | pmc = 2173330| doi=10.1083/jcb.200111002}} 16. ^{{cite journal |vauthors=Haering CH, Löwe J, Hochwagen A, Nasmyth K | title = Molecular architecture of SMC proteins and the yeast cohesin complex.| journal = Mol. Cell| volume = 9 | issue = 4 | pages = 773–788| year = 2002 | pmid = 11983169 | doi=10.1016/S1097-2765(02)00515-4}} 17. ^{{cite journal |vauthors=Hirano M, Hirano T | title = Hinge-mediated dimerization of SMC protein is essential for its dynamic interaction with DNA| journal = EMBO J.| volume = 21 | issue = 21 | pages = 5733–5744| year = 2002 | pmid = 12411491 | pmc = 131072| doi=10.1093/emboj/cdf575}} 4 : EC 3.6.3|Cell biology|Mitosis|Cell cycle |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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。