The most common and most likely answer to this crossword clue is the 5 letter word TEXAS
I've seen this crossword clue in The Sunday Telegraph
T
E
X
A
S
More clues leading to the result TEXAS
- State: 'Times to invest in brewing products'
- State taxes centrally overthrown
- State vote held in Assam and Darjeeling?
- Group of Scots, perhaps with back-up guitar
- Part of US having taxes evenly redistributed?
- State meals must be taken around ten
- State: ‘Times to invest in brewing products’
- State temperature trials losing money
- State of silent exasperation
- Animated sex at the upper deck of a boat
Buddy explains!

The straight part
We know that "Part of US" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of us = texas.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.