2c4c: Difference between revisions

Semaphorins are extracellular cell guidance cues that govern cytoskeletal, dynamics during neuronal and vascular development. MICAL (molecule, interacting with CasL) is a multidomain cytosolic protein with a putative, flavoprotein monooxygenase (MO) region required for semaphorin-plexin, repulsive axon guidance. Here, we report the 1.45-A resolution crystal, structure of the FAD-containing MO domain of mouse MICAL-1 (residues, 1-489). The topology most closely resembles that of the NADPH-dependent, flavoenzyme p-hydroxybenzoate hydroxylase (PHBH). Comparison of structures, before and after reaction with NADPH reveals that, as in PHBH, the flavin, ring can switch between two discrete positions. In contrast with other, MOs, this conformational switch is coupled with the opening of a channel, to the active site, suggestive of a protein substrate. In support of this, hypothesis, distinctive structural features highlight putative, protein-binding sites in suitable proximity to the active site entrance., The unusual juxtaposition of this N-terminal MO (hydroxylase) activity, with the characteristics of a multiprotein-binding scaffold exhibited by, the C-terminal portion of the MICALs represents a unique combination of, functionality to mediate signaling.

2C4C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with CL and FAD as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2C4C OCA].  

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