Related Experiment Videos
Sequence similarities between chicken intestinal 110-kDa ATPase and myosin I-like enzymes
1Department of Biochemistry, University of Texas Health Center, Tyler 75710.
Abstract:
We report the partial amino acid sequence of chicken intestinal microvillar 110-kDa protein that, as a complex with calmodulin, has previously been shown to exhibit myosin-like ATPase and actin-binding activities. The sequence shows a high degree of similarity to the sequence of a novel vertebrate myosin I-like heavy chain encoded by a cDNA isolated from bovine intestine. This confirms that the bovine and chicken proteins are the first examples of Acanthamoeba myosin I-like proteins from higher eukaryotes. Comparison of available structural and functional data leads us to postulate that the myosin I family of proteins result from the fusion of a conserved myosin headlike motor domain, with variable COOH-terminal domains responsible for binding to specific intracellular structures.
Insights
Chicken and bovine intestinal proteins are the first higher eukaryotic examples of Acanthamoeba myosin I-like proteins, sharing structural similarities. This suggests myosin I proteins evolved from fused motor and variable binding domains.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Chicken intestinal microvillar 110-kDa protein, complexed with calmodulin, exhibits myosin-like ATPase and actin-binding activities.
- Myosin I-like proteins are found in various organisms, playing roles in cellular processes.
Purpose of the Study:
- To determine the partial amino acid sequence of the chicken intestinal 110-kDa protein.
- To compare the chicken protein's sequence with known myosin I-like proteins.
- To elucidate the evolutionary origins and structural characteristics of the myosin I family.
Main Methods:
- Partial amino acid sequencing of chicken intestinal microvillar 110-kDa protein.
- Sequence homology comparison with bovine intestinal myosin I-like heavy chain cDNA.
- Analysis of existing structural and functional data for myosin I proteins.
Main Results:
- The partial amino acid sequence of the chicken protein shows high similarity to a novel vertebrate myosin I-like heavy chain from bovine intestine.
- This finding identifies the bovine and chicken proteins as the first Acanthamoeba myosin I-like proteins identified in higher eukaryotes.
- Structural and functional data suggest a conserved myosin motor domain fused with variable COOH-terminal domains in the myosin I family.
Conclusions:
- The chicken and bovine proteins represent higher eukaryotic homologs of Acanthamoeba myosin I.
- The myosin I family likely evolved through the fusion of a conserved motor domain with specific intracellular structure-binding domains.
- This study provides insights into the evolution and structural diversity of myosin proteins.