If you have Windows clients, it is good to have an AV to make sure you do not send anything infected, but if it is not it is not worth it.The AVs for Linux do not provide realtime protection. They are only for scanning. Many of them don't even detect Linux malware, due to lack of appropriate definitions; they only detect Windows malware. So you can use them to prevent infecting Windows users, and to scan your Windows dual boot, but they won't protect your Linux installation.
If you want to scan your Linux, Clam might be a good choice -- at least it is made with Linux in mind.