If you're overweight, your protein target should be based on your lean mass, not your excess mass. While you can have more, you're likely better off conserving the calories.
Also, personally, I tend to recommend at least 0.5g fat to 1g protein. This seems to be pretty close to what you get from a lot of healthy protein sources and given that you actually need a certain amount of essential fatty acids for your body to function, I find this helps from digestion, glucose control, satiety and even weight loss.