  To elucidate the influence of shear flow on the generation of magnetic field
(the dynamo effect), we study the kinematic limit where the magnetic field does
not backreact on the velocity field. By non-perturbatively incorporating the
effect of shear in a helically forced turbulence, we show that turbulence
intensity and turbulent transport coefficients (turbulent viscosity, $\alpha$
and $\beta$ effect) are enhanced by a weak shear while strongly suppressed for
strong shear. In particular, $\beta$ is shown to be much more strongly
suppressed than $\alpha$ effect. We discuss its important implications for
dynamo efficiency, i.e. on the scaling of the dynamo number with differential
rotation.
