Summary
We identified several open reading frames between the regions encoding calmodulin and ubiquitin-EP52/1 in the genome ofTrypanosoma brucei. One of these, EFH5, encodes a protein 192 amino acids long. The EFH5 transcript is present in poly(A)+ mRNA and is present at similar levels in the mammalian bloodstream form and the insect procyclic form. EFH5 contains four EF-hand homolog domains, two of which are inferred to bind Ca2+ ions. We expressed EFH5 as a fusion protein inEscherichia coli and demonstrated calcium-binding activity of the fusion protein using the45Ca-overlay technique. The function of EFH5 remains unknown; however, as the fourth EF-hand homolog identified in trypanosomes, it attests to the broad range of functions assumed by calcium functioning as a second messenger. EFH5, which is most closely related to LAV1-2 fromPhysarum, represents a distinct subfamily among the EF-hand-containing proteins.
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Communicated by D. Thomas
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Wong, S., Kretsinger, R.H. & Campbell, D.A. Identification of a new EF-hand superfamily member fromTrypanosoma brucei . Molec. Gen. Genet. 233, 225–230 (1992). https://doi.org/10.1007/BF00587583
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DOI: https://doi.org/10.1007/BF00587583