ISSN:
1573-2657
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary We have determined by protein chemistry methods the amino acid sequence of light chain 2 fromAcanthamoeba castellanii myosin-II (ALC2). This is the first reported sequence for any protozoan myosin light chain. ALC2 consists of 154 amino acid residues, including a single residue of His and two residues each of Pro and Tyr, and lacks Cys and Trp. The N-terminus is blocked, and if an N-terminal acetyl group is assumed, ALC2 has a calculated molecular weight of 17657. ALC2 is an acidic protein, with a calculated net charge of — 7 at pH 7. The sequence of ALC2 is most similar to those of the calmodulins (identity approximately 35%, followed by myosin regulatory light chains. ALC2 appears to lack the potential N-terminal phosphorylation site and single Ca2+-binding site in region I which are characteristic of most myosin regulatory light chains. Instead, ALC2, unlike any other myosin light chain characterized to date, may have a functional Ca2+-binding site only in region II, suggesting a novel role of ALC2 in the Ca2+ regulation of the activity ofAcanthamoeba myosin-II.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01738443
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