helical surface

This can be solved by allowing ln(z) to operate on a helical surface instead.

If , the handedness determined by the sign of , the wavefront is shaped as a single helical surface, with a step length equal to the wavelength .

In lefthanded β helices, the strands themselves are quite straight and untwisted; the resulting helical surfaces are nearly flat, forming a regular triangular prism shape, as shown for the 1QRE archaeal carbonic anhydrase at right.