One of the top defensive linemen in the free-agency pool is off the market.

Michael Smith of ESPN.com reports that end Justin Smith, formerly of the Bengals, will now play for the 49ers.  He’ll receive a six-year, $45 million contract with $20 million in guaranteed money.

The Vikings had hoped to woo the fourth overall pick in the 2001 draft, but he never got out of San Fran.

Smith is regarded primarily as a run-stopper; he had only two sacks in 2007.  But he is durable and it’s hard to assess his ability given that he Bengals defense hasn’t been very good over the past couple of years.