After re-reading your message, I think the "famous Pettuses " you have in mind could be Sir John Pettus, Kt., and his next younger brother, Thomas. Both Sir John and Thomas were prominent merchants of Norwich, England, who held the office of mayor in 1608 and 1614, respectively.
Two of Thomas's sons, Thomas and Theodore, emigrated to Virgina. Thomas was quite prominent in Virginia as a member of the Council of State (Governor's Council) and as a colonel of the Virginia militia. Sir John's youngest brother, William, m. Elizabeth Rolfe, mentioned in my previous reply to your query.
My fifth ggf, Thomas Pettus of Lunenburg Co., Va., represented his county in the House of Burgesses just prior to the Revolution. He m. Amey Walker in 1735. A family bible identifies Thomas's parents as "John Pettus and his wife Ann." The identity of John Pettus has been the subject of controversy. That controversy was a motivating factor for me to begin researching the early generations of the Pettus family in Virginia.