Exchange 2000 in Mixed NT Environment

I have a Windows NT 4.0 network, PDC, BDC’s etc.
My Exchange 5.5 server needs replacing. I would like to upgrade to Exchange 2000 on my new server. I won’t be able to upgrade my PDC and BDCs for awhile. Can I put an Exchange 2000 server on a Windows NT network without upgrading the whole network?
The Exchange 2000 config is as follows.
Win2K Member Server, Exchange 2000 in Native
Mode on a Dell Poweredge Server in a Windows NT 4.0 Domain.
Thanks