Sandbox 154: Difference between revisions
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[[image:2zwh_domain_colours2.png|thumb|Domains of F-actin monomer|frame|left]] | [[image:2zwh_domain_colours2.png|thumb|Domains of F-actin monomer|frame|left]] | ||
==== Polymer ==== | ==== Polymer ==== | ||
F-actin has the appearance of two right-handed helices, with a gradual twist around one another. It is actually composed of repeats of 13 actin units for every 6 left-handed turns, spanning a length of 350 Å<ref name="Holmes2"/>. Including the ADP and Ca<sup>2+</sup>, the F-actin molecule as shown here consists of 377 residues (43kDa), two major domains separated by a nucleotide-binding cleft<ref name="oda" />. Depending on the state of the bound nucleotide, the most stable conformation of F-actin changes. In its ATP and ADP + Pi nucleotide bound states, it has a closed binding cleft. In its ADP only bound state, it has a wider binding cleft<ref name="Pfaendtner">. A characteristic trait of actin is that the domains remain twisted relative to one another, despite the nucleotide-state-dependent conformational changes<ref name="oda" />. | F-actin has the appearance of two right-handed helices, with a gradual twist around one another. It is actually composed of repeats of 13 actin units for every 6 left-handed turns, spanning a length of 350 Å<ref name="Holmes2"/>. Including the ADP and Ca<sup>2+</sup>, the F-actin molecule as shown here consists of 377 residues (43kDa), two major domains separated by a nucleotide-binding cleft<ref name="oda" />. Depending on the state of the bound nucleotide, the most stable conformation of F-actin changes. In its ATP and ADP + Pi nucleotide bound states, it has a closed binding cleft. In its ADP only bound state, it has a wider binding cleft<ref name="Pfaendtner"/>. A characteristic trait of actin is that the domains remain twisted relative to one another, despite the nucleotide-state-dependent conformational changes<ref name="oda" />. | ||
=== Nucleotide-State-Dependent Conformational Changes === | === Nucleotide-State-Dependent Conformational Changes === | ||