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Dissecting the domain structure of Cdc4p, a myosin essential light chain involved in Schizosaccharomyces pombe cytokinesis.
- Source :
-
Biochemistry [Biochemistry] 2005 Sep 13; Vol. 44 (36), pp. 12136-48. - Publication Year :
- 2005
-
Abstract
- Cytokinesis is the process by which one cell divides into two. Key in the cytokinetic mechanism of Schizosaccharomyces pombe is the contractile ring myosin, which consists of two heavy chains (Myo2p), two essential light chains (Cdc4p), and two regulatory light chains (Rlc1p). Cdc4p is a dumbbell-shaped EF-hand protein composed of N- and C-terminal domains separated by a flexible linker. The properties of these two domains are of particular interest because each is hypothesized to have independent functions in binding different components of the cytokinesis machinery. To help define these properties, we used NMR spectroscopy to compare the structure, stability, and dynamics of the isolated N- and C-terminal domains with one another and with native Cdc4p. On the basis of invariant chemical shifts, the N-domain retains the same structure in isolation as in the context of the full-length Cdc4p, whereas the C-domain appears markedly perturbed. This perturbation results from intramolecular binding of the residual linker sequence at the N-terminus of the C-domain in a mode similar to that used by native Cdc4p to associate with target polypeptide sequences. NMR relaxation, thermal denaturation, and amide hydrogen exchange experiments also indicate that the C-domain is less stable and more dynamic than the N-domain, both in isolation and in the full-length protein. We hypothesize that these properties reflect a conformational plasticity of the C-domain, which may allow Cdc4p to interact with several regulatory or contractile ring proteins necessary for cytokinesis.
- Subjects :
- Amino Acid Sequence
Cytoskeletal Proteins
Glycine genetics
Glycine metabolism
Models, Molecular
Molecular Sequence Data
Nuclear Magnetic Resonance, Biomolecular
Protein Denaturation
Protein Folding
Protein Structure, Secondary
Protein Structure, Tertiary
Schizosaccharomyces chemistry
Schizosaccharomyces pombe Proteins
Sequence Alignment
Sequence Homology, Amino Acid
Temperature
Threonine genetics
Threonine metabolism
Cell Cycle Proteins chemistry
Cell Cycle Proteins metabolism
Cytokinesis
F-Box Proteins chemistry
F-Box Proteins metabolism
Myosin Light Chains chemistry
Myosin Light Chains metabolism
Schizosaccharomyces cytology
Schizosaccharomyces metabolism
Ubiquitin-Protein Ligases chemistry
Ubiquitin-Protein Ligases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0006-2960
- Volume :
- 44
- Issue :
- 36
- Database :
- MEDLINE
- Journal :
- Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 16142912
- Full Text :
- https://doi.org/10.1021/bi050641c