The structure is shown of aniline, one of the two pertinent reference molecules for the discussion of the properties of PABA, the para-aminobenzoic acid. As with PABA, notice that the amino group is NOT sp²-hybridized but the N-atom is clearly pyramidal!
The MO eigenvalues of aniline are provided in the file behind the link eigenvalues. Find the eigenvalues of the HOMO and the LUMO and compare the HOMO-LUMO gap to the respective gaps in PABA and benzoic acid.