[Nimitz]

Hey all, I'm having some trouble pinning down the lone pairs on this Mimisine molecule.
The problem says to complete the structure of a line-structure drawing of Mimisine by drawing in the Hydrogens and lone pairs, which, as you can see in the linked image, I've mostly done. What's giving me trouble here is the central-ish Nitrogen atom.
I initially had a lone pair tacked onto the N atom, but when I looked at a 3D model of the molecule the Nitrogen appeared to have a Trigonal Planar shape about it, which to the extent of my knowledge is impossible with three bonds plus a lone pair, which would necessitate an sp3 hybridization with a tetrahedral group geometry and pyramidal shape.
The issue is that without the lone pair, the Nitrogen doesn't have an octet and the entire molecule has two electrons that are unaccounted for (on the current iteration I count 74 instead of 76, which it should have). I can't find any other place to fit them in, but I just don't know how it can be possible for the Nitrogen to have a lone pair while also maintaining the trigonal planar geometry.
Photo of the molecule/ my attempt at the problem: http://i.imgur.com/wzWj6jI.jpg

[AWK]

Think about about sp² + unhybridized p orbital.

Though it is not your fault, but compound is called L-mimosine ((2S)-2-Amino-3-(3-hydroxy-4-oxopyridin-1-yl)propanoic acid).

[Nimitz]

So the lone pair is in the unhybridized p-orbital? Wouldn't that give a 90-degree angle between the lone pair and the bonding orbitals? So if that is the case, the Nitrogen is being held in that unfavorable electron group arrangement by its bonds with the neighboring carbons?

[AWK]

Do not think only about nitrogen atom, think about the whole ring.

[Nimitz]

The "lone pair" is delocalized over part of the ring? In any case I've already turned in the assignment, I just want to know what's going on here.

[AWK]

http://actachemscand.org/pdf/acta_vol_27_p0164-0176.pdf