  We consider the one-loop five-graviton amplitude in type II string theory
calculated in the light-cone gauge. Although it is not possible to explicitly
evaluate the integrals over the positions of the vertex operators, a low-energy
expansion can be obtained, which can then be used to infer terms in the
low-energy effective action. After subtracting diagrams due to known D^{2n}R^4
terms, we show the absence of one-loop R^5 and D^2R^5 terms and determine the
exact structure of the one-loop D^4R^5 terms where, interestingly, the
coefficient in front of the D^4R^5 terms is identical to the coefficient in
front of the D^6R^4 term. Finally, we show that, up to D^6R^4 ~ D^4R^5, the
\epsilon_{10} terms package together with the t_8 terms in the usual
combination (t_8t_8\pm{1/8}\epsilon_{10}\epsilon_{10}).
