U.S. Bank sued Bank of America over Countrywide loans. Bank of America has also made several moves recently to shore up capital. The bank struck a deal to sell preferred stock and warrants to billionaire investor Warren Buffett for $5 billion. Bank of America has also reportedly slashed its mortgage business and has also cut its China Construction Bank stake. -- Written by Robert Holmes in Boston. >To contact the writer of this article, click here: Robert Holmes. >To follow Robert Holmes on Twitter, go to http://twitter.com/RobTheStreet. >To submit a news tip, send an email to: email@example.com.