Isolation of a novel calcium‐binding protein from <i>streptomyces erythreus</i>

Abstract

A small, acidic protein has been isolated from Streptomyces erythreus . Like eukaryotic calcium‐binding proteins, it exhibits a calcium‐dependent shift in mobility on SDS‐polyacrylamide gel electrophoresis. Its N‐terminal amino acid sequence contains a potential calcium‐binding site which shows striking homology to the corresponding sites in calmodulin. Direct binding studies using 45 Ca showed that the protein, either purified or in cell‐free extracts, is capable of binding calcium with high affinity.