Sigmalike

This is at least defensible, for the twisting of the chela is in itself a structural feature that is sigmalike; that is, the twisted chela is intermediate, in respect to the shape of the spicular axis, between the sigma and the normal chela, although in other respects it is a perfectly differentiated chela.

They predicted that there should be other sigmalike factors that would select other classes of promoters in response to the cell's needs.

agents which stimulate transcription suggest that sigmalike factors also exist for the eukaryotic polymerases.