That board has a PCIE x16 gen 2 and it should support the card. Question is the PSU.
I think GTX 550 Tis need at least one 6-pin auxiliary PCIE power connectors. The card need something around 120W at peak.
What is your PSU brand and model. What is your current graphics card on that system? Does the PSU have PCIE connectors/cables? If it's a decent 400W or so it would have at least two 6 or 6+2 pins.