DDR5 does not exist so you must have meant GDDR5.
In any case, the type of RAM on a graphics card has no bearing on weather or not the card will "fit" on your motherboard and in general, any PCIe GPU will "fit" on any motherboard with a PCIe x16 slot as long as the motherboard manufacturer did not do something stupid with their board layout or the GPU manufacturer ignored the PCIe clearance specs.
Mechanical fit inside the computer case - at least for the longer cards - is a more common problem than motherboard fit and compatibility.