Prohibited Transaction if Self-Directed Investment???

[Christine Roberts]

An officer (and less than 10% owner) of a professional partnership also provides professional services to a company that forms a real estate limited partnership (RELP).

The officer wants to invest his self-directed 401(k) account in part, in the RELP. The professional partnership's 401(k) plan has a corporate trustee, so the officer is not a fiduciary by virtue of being plan trustee.

Is it a PT if the officer invests only for his own account? Is there an unrelated business taxable income issue?