1l2p: Difference between revisions

Revision as of 23:28, 2 May 2008

ATP Synthase b Subunit Dimerization Domain

OverviewOverview

The b subunit of E. coli F(0)F(1)-ATPase links the peripheral F(1) subunits to the membrane-integral F(0) portion and functions as a "stator", preventing rotation of F(1). The b subunit is present as a dimer in ATP synthase, and residues 62-122 are required to mediate dimerization. To understand how the b subunit dimer is formed, we have studied the structure of the isolated dimerization domain, b(62-122). Analytical ultracentrifugation and solution small-angle X-ray scattering (SAXS) indicate that the b(62-122) dimer is extremely elongated, with a frictional ratio of 1.60, a maximal dimension of 95 A, and a radius of gyration of 27 A, values that are consistent with an alpha-helical coiled-coil structure. The crystal structure of b(62-122) has been solved and refined to 1.55 A. The protein crystallized as an isolated, monomeric alpha helix with a length of 90 A. Combining the crystal structure of monomeric b(62-122) with SAXS data from the dimer in solution, we have constructed a model for the b(62-122) dimer in which the two helices form a coiled coil with a right-handed superhelical twist. Analysis of b sequences from E. coli and other prokaryotes indicates conservation of an undecad repeat, which is characteristic of a right-handed coiled coil and consistent with our structural model. Mutation of residue Arg-83, which interrupts the undecad pattern, to alanine markedly stabilized the dimer, as expected for the proposed two-stranded, right-handed coiled-coil structure.

About this StructureAbout this Structure

1L2P is a Single protein structure of sequence from Escherichia coli. The following page contains interesting information on the relation of 1L2P with [ATP Synthase]. Full crystallographic information is available from OCA.

ReferenceReference

The "second stalk" of Escherichia coli ATP synthase: structure of the isolated dimerization domain., Del Rizzo PA, Bi Y, Dunn SD, Shilton BH, Biochemistry. 2002 May 28;41(21):6875-84. PMID:12022893 Page seeded by OCA on Fri May 2 23:28:27 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1l2p.jpg|left|200px]]
- {{Structure
+<!--
-|PDB= 1l2p |SIZE=350|CAPTION= <scene name='initialview01'>1l2p</scene>, resolution 1.55&Aring;
+The line below this paragraph, containing "STRUCTURE_1l2p", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND=
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Iron-chelate-transporting_ATPase Iron-chelate-transporting ATPase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.3.34 3.6.3.34] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1l2p|  PDB=1l2p  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1l2p FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1l2p OCA], [http://www.ebi.ac.uk/pdbsum/1l2p PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1l2p RCSB]</span>
-}}
 '''ATP Synthase b Subunit Dimerization Domain'''
@@ Line 31: / Line 28: @@
 [[Category: Rizzo, P A.Del.]]
 [[Category: Shilton, B H.]]
-[[Category: alpha helix]]
+[[Category: Alpha helix]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 23:28:27 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:57:10 2008''