Factor IX: Difference between revisions

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To identify the exact locations of bound Mg2+ ions, crystal structures comparisons were made between Mg2+-free and Mg2+-bound conditions. In the Mg2+-free conditions, Mg-1, Mg-7, and Mg-8, were replaced by Ca2+ ions which induced an elongation of the bond between the ion and an oxygen atom from a distance of 2.11 to 2.34 Å. This small change in distance induces a [[rotation of 4 degrees of FIX]]. This suggests that the magnisuim ions induce a closed form conformation that contributes to the tight association of the Gla domain. This situation probably arises mainly from a difference in length between O–Mg–O and O–Ca–O bridges.

The Gla domain perhaps also interacts with factor VIIIa via Mg2+-binding sites. Membrane bound FIXa forms an arched structure which is seen in the spatial relationship among the Gla, epidermal growth factor, and serine protease domains. This arched allows for the formation of a concave surface on the right side of FIXa and acts as a binding site for factor VIIIa. The Mg-8 ion points toward this concave surface making it ideal in the interaction between FIXa and GVIIIa. Similarly, Mg-8 may contribute to the binding to factors VIIa and X.

Factor IX: Difference between revisions

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Revision as of 22:33, 26 April 2009 view source Nadia Dorochko (talk \| contribs) 420 edits No edit summary ← Older edit		Revision as of 22:36, 26 April 2009 view source Nadia Dorochko (talk \| contribs) 420 edits No edit summary Newer edit →
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	To identify the exact locations of bound Mg2+ ions, crystal structures comparisons were made between Mg2+-free and Mg2+-bound conditions. In the Mg2+-free conditions, Mg-1, Mg-7, and Mg-8, were replaced by Ca2+ ions which induced an elongation of the bond between the ion and an oxygen atom from a distance of 2.11 to 2.34 Å. This small change in distance induces a [[rotation of 4 degrees of FIX]]. This suggests that the magnisuim ions induce a closed form conformation that contributes to the tight association of the Gla domain. This situation probably arises mainly from a difference in length between O–Mg–O and O–Ca–O bridges.		To identify the exact locations of bound Mg2+ ions, crystal structures comparisons were made between Mg2+-free and Mg2+-bound conditions. In the Mg2+-free conditions, Mg-1, Mg-7, and Mg-8, were replaced by Ca2+ ions which induced an elongation of the bond between the ion and an oxygen atom from a distance of 2.11 to 2.34 Å. This small change in distance induces a [[rotation of 4 degrees of FIX]]. This suggests that the magnisuim ions induce a closed form conformation that contributes to the tight association of the Gla domain. This situation probably arises mainly from a difference in length between O–Mg–O and O–Ca–O bridges.

			The Gla domain perhaps also interacts with factor VIIIa via Mg2+-binding sites. Membrane bound FIXa forms an arched structure which is seen in the spatial relationship among the Gla, epidermal growth factor, and serine protease domains. This arched allows for the formation of a concave surface on the right side of FIXa and acts as a binding site for factor VIIIa. The Mg-8 ion points toward this concave surface making it ideal in the interaction between FIXa and GVIIIa. Similarly, Mg-8 may contribute to the binding to factors VIIa and X.