4akr: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[ | ==Crystal Structure of the cytoplasmic actin capping protein Cap32_34 from Dictyostelium discoideum== | ||
<StructureSection load='4akr' size='340' side='right' caption='[[4akr]], [[Resolution|resolution]] 2.20Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4akr]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Dictyostelium_discoideum Dictyostelium discoideum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AKR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4AKR FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4akr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4akr OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4akr RCSB], [http://www.ebi.ac.uk/pdbsum/4akr PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
ABSTRACT: BACKGROUND: Capping protein (CP), also known as CapZ in muscle cells and Cap32/34 in Dictyostelium discoideum, plays a major role in regulating actin filament dynamics. CP is a ubiquitously expressed heterodimer comprising an alpha- and beta-subunit. It tightly binds to the fast growing end of actin filaments, thereby functioning as a "cap" by blocking the addition and loss of actin subunits. Vertebrates contain two somatic variants of CP, one being primarily found at the cell periphery of non-muscle tissues while the other is mainly localized at the Z-discs of skeletal muscles. RESULTS: To elucidate structural and functional differences between cytoplasmic and sarcomercic CP variants, we have solved the atomic structure of Cap32/34 (32 = beta- and 34 = alpha-subunit) from the cellular slime mold Dictyostelium at 2.2 A resolution and compared it to that of chicken muscle CapZ. The two homologs display a similar overall arrangement including the attached alpha-subunit C-terminus (alpha-tentacle) and the flexible beta-tentacle. Nevertheless, the structures exhibit marked differences suggesting considerable structural flexibility within the alpha-subunit. In the alpha-subunit we observed a bending motion of the beta-sheet region located opposite to the position of the C-terminal beta-tentacle towards the antiparallel helices that interconnect the heterodimer. Recently, a two domain twisting attributed mainly to the beta-subunit has been reported. At the hinge of these two domains Cap32/34 contains an elongated and highly flexible loop, which has been reported to be important for the interaction of cytoplasmic CP with actin and might contribute to the more dynamic actin-binding of cytoplasmic compared to sarcomeric CP (CapZ). CONCLUSIONS: The structure of Cap32/34 from Dictyostelium discoideum allowed a detailed analysis and comparison between the cytoplasmic and sarcomeric variants of CP. Significant structural flexibility could particularly be found within the alpha-subunit, a loop region in the beta-subunit, and the surface of the alpha-globule where the amino acid differences between the cytoplasmic and sarcomeric mammalian CP are located. Hence, the crystal structure of Cap32/34 raises the possibility of different binding behaviours of the CP variants toward the barbed end of actin filaments, a feature, which might have arisen from adaptation to different environments. | |||
Conservation and divergence between cytoplasmic and muscle-specific actin capping proteins: insights from the crystal structure of cytoplasmic Cap32/34 from Dictyostelium discoideum.,Eckert C, Goretzki A, Faberova M, Kollmar M BMC Struct Biol. 2012 Jun 1;12(1):12. PMID:22657106<ref>PMID:22657106</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | |||
*[[F-actin capping protein|F-actin capping protein]] | |||
== | == References == | ||
[[ | <references/> | ||
__TOC__ | |||
== | </StructureSection> | ||
< | |||
[[Category: Dictyostelium discoideum]] | [[Category: Dictyostelium discoideum]] | ||
[[Category: Eckert, C.]] | [[Category: Eckert, C.]] | ||