regarding four-way closure in structural geology

I understand the term "four-way closure" to be a dome (structural). If that is what you mean...

In that case the 2 structures are similar, but domes are rather symmetrical, whiles anticlines are very asymmetrical, to the extend that we only consider them having to limbs. Although technically speaking anticlines have four, just like domes. Those limbs are called periclines. It's all just convention, both four-way closures and anticlines are folded structures that have an "ending" at some point, it's just that four-way closures are more symmetrical.