Solution structure of the chicken cysteine-rich protein, CRP1, a double-LIM protein implicated in muscle differentiation.
The mechanism by which the contractile machinery of muscle is assembled and maintained is not well-understood. Members of the cysteine-rich protein (CRP) family have been implicated in these processes. Three vertebrate CRPs (CRP1-3) that exhibit developmentally regulated muscle-specific expression have been identified. All three proteins are associated with the actin cytoskeleton, and one has been shown to be required for striated muscle structure and function. The vertebrate CRPs identified to date display a similar molecular architecture; each protein is comprised of two tandemly arrayed LIM domains, protein-binding motifs found in a number of proteins with roles in cell differentiation. Each LIM domain coordinates two Zn(II) ions that are bound independently in CCHC (C=Cys, H=His) and CCCC modules. Here we describe the solution structure of chicken CRP1 determined by homonuclear and 1H-15N heteronuclear magnetic resonance spectroscopy. Comparison of the structures of the two LIM domains of CRP1 reveals a high degree of similarity in their tertiary folds. In addition, the two component LIM domains represent two completely independent folding units and exhibit no apparent interactions with each other. The structural independence and spatial separation of the two LIM domains of CRP1 are compatible with an adapter or linker role for the protein.
Yao
X
X
Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Maryland Baltimore County 21250, USA.
Pérez-Alvarado
G C
GC
Louis
H A
HA
Pomiès
P
P
Hatt
C
C
Summers
M F
MF
Beckerle
M C
MC
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D002352:Carrier Proteins / Q000737:chemistry* / Q000502:physiology; D002454:Cell Differentiation; D002645:Chickens; D018360:Crystallography, X-Ray; D060588:LIM Domain Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000737:chemistry / Q000166:cytology*; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012996:Solutions; D016335:Zinc Fingers / Q000502:physiology
D048868:Adaptor Proteins, Signal Transducing; D030161:Avian Proteins; D002352:Carrier Proteins; D060588:LIM Domain Proteins; D012996:Solutions