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. Author manuscript; available in PMC: 2010 Apr 9.
Published in final edited form as: Mol Cell. 2008 Mar 14;29(5):563–576. doi: 10.1016/j.molcel.2007.12.017

Figure 2. Overview of the SRPK1:ASF/SF2 Complex Structure.

Figure 2

(A) Overall structure of the complex shown in two orientations. The kinase (SRPK1) and substrate (ASF/SF2) are represented in gray and gold, respectively. The dotted line marks the lack of electron density of four residues connecting the RRM and RS domains of the substrate. A molecule of AMP-PNP lies between a cleft between the small and large lobes of SRPK1. The phosphoserine (P-Ser) shown in gold is located near the P+1 loop of the kinase.

(B) Ribbon diagram of the RRM2 domain of ASF/SF2 (left panel). The right panel shows a canonical RRM fold from the RNP domain of U1 A protein (Nagai et al., 1990). Note that the strand βN is absent in the canonical RRM fold.

(C) Amino acid sequence of the ASF/SF2 fragment used in structure determination and multiple sequence alignment of this fragment with other SR proteins containing two RRMs. The secondary structural elements seen in the structure are assigned to the sequence of the RRM2 domain of ASF/SF2. Residues that are disordered are colored gray. The unique RRM2 SWQDLKD sequence is shaded by a yellow box. The kinase-contacting residues within the RRM2 domain are colored blue. The cysteine residue denoted by green makes a disulfide bond with a symmetry-related substrate molecule. The previously identified docking motif is highlighted by a red box.