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Atomic-Resolution Structures of the APC/C Subunits Apc4 and the Apc5 N-Terminal Domain.

Cronin NB, Yang J, Zhang Z, Kulkarni K, Chang L, Yamano H, Barford D - J. Mol. Biol. (2015)

Bottom Line: In a separate study, we had fitted these atomic models to a 3.6-Å-resolution cryo-electron microscopy map of the APC/C.We describe how, in the context of the APC/C, regions of Apc4 disordered in the crystal assume order through contacts to Apc5, whereas Apc5(N) shows small conformational changes relative to its crystal structure.We discuss the complementary approaches of high-resolution electron microscopy and protein crystallography to the structure determination of subunits of multimeric complexes.

View Article: PubMed Central - PubMed

Affiliation: Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom.

No MeSH data available.


Related in: MedlinePlus

The Apc4–Apc5 protein interface orders regions of Apc4HBD. (a) Human Apc4–Apc5 as organized in the APC/C with the X-ray structure of Apc4 (red) superimposed onto the EM coordinates (brown). The Apc4–Apc5 interface is shown. (b) As in (a) but without Apc5. (c) Stereoview showing that the crystal structures of X. laevis and human Apc4 are very similar (RMSD is 2.1 Å).
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f0015: The Apc4–Apc5 protein interface orders regions of Apc4HBD. (a) Human Apc4–Apc5 as organized in the APC/C with the X-ray structure of Apc4 (red) superimposed onto the EM coordinates (brown). The Apc4–Apc5 interface is shown. (b) As in (a) but without Apc5. (c) Stereoview showing that the crystal structures of X. laevis and human Apc4 are very similar (RMSD is 2.1 Å).

Mentions: There are extensive contacts between Apc4HBD and both the bottom surface and the strand surface of the second, third and fourth blades of Apc4WD40 (Fig. 1a). This packing interaction confers stability to the tertiary structure of Apc4, and small-angle X-ray scattering (SAXS) analysis confirmed that the solution structure is consistent with the X-ray structure (Supplementary Fig. 2c). Moreover, superimposing the Apc4 model from the crystal structure onto the EM-derived structure [44] showed that, except for the ordering of regions of Apc4HBD, the conformation of Apc4 does not change in the context of the APC/C, indicating that the HBD and WD40 domains are rigidly associated (Fig. 2a and b). Human and X. laevis Apc4 are also very similar, differing only for residues 120–130 (X. laevis Apc4 numbering) within the shorter WD40 insert that is an α-helix in the X. laevis Apc4 structure in contrast to a predominantly disordered loop structure in human Apc4 (Fig. 2c and Table 2).


Atomic-Resolution Structures of the APC/C Subunits Apc4 and the Apc5 N-Terminal Domain.

Cronin NB, Yang J, Zhang Z, Kulkarni K, Chang L, Yamano H, Barford D - J. Mol. Biol. (2015)

The Apc4–Apc5 protein interface orders regions of Apc4HBD. (a) Human Apc4–Apc5 as organized in the APC/C with the X-ray structure of Apc4 (red) superimposed onto the EM coordinates (brown). The Apc4–Apc5 interface is shown. (b) As in (a) but without Apc5. (c) Stereoview showing that the crystal structures of X. laevis and human Apc4 are very similar (RMSD is 2.1 Å).
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590430&req=5

f0015: The Apc4–Apc5 protein interface orders regions of Apc4HBD. (a) Human Apc4–Apc5 as organized in the APC/C with the X-ray structure of Apc4 (red) superimposed onto the EM coordinates (brown). The Apc4–Apc5 interface is shown. (b) As in (a) but without Apc5. (c) Stereoview showing that the crystal structures of X. laevis and human Apc4 are very similar (RMSD is 2.1 Å).
Mentions: There are extensive contacts between Apc4HBD and both the bottom surface and the strand surface of the second, third and fourth blades of Apc4WD40 (Fig. 1a). This packing interaction confers stability to the tertiary structure of Apc4, and small-angle X-ray scattering (SAXS) analysis confirmed that the solution structure is consistent with the X-ray structure (Supplementary Fig. 2c). Moreover, superimposing the Apc4 model from the crystal structure onto the EM-derived structure [44] showed that, except for the ordering of regions of Apc4HBD, the conformation of Apc4 does not change in the context of the APC/C, indicating that the HBD and WD40 domains are rigidly associated (Fig. 2a and b). Human and X. laevis Apc4 are also very similar, differing only for residues 120–130 (X. laevis Apc4 numbering) within the shorter WD40 insert that is an α-helix in the X. laevis Apc4 structure in contrast to a predominantly disordered loop structure in human Apc4 (Fig. 2c and Table 2).

Bottom Line: In a separate study, we had fitted these atomic models to a 3.6-Å-resolution cryo-electron microscopy map of the APC/C.We describe how, in the context of the APC/C, regions of Apc4 disordered in the crystal assume order through contacts to Apc5, whereas Apc5(N) shows small conformational changes relative to its crystal structure.We discuss the complementary approaches of high-resolution electron microscopy and protein crystallography to the structure determination of subunits of multimeric complexes.

View Article: PubMed Central - PubMed

Affiliation: Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom.

No MeSH data available.


Related in: MedlinePlus