GMAT Verbal Section | Re: Bossy verbs

Hi,

I saw the following from Manhattan GMAT SCbook:

They demanded that the store be closed.

Could anyone identify the sentence structure of the above?

I suspect "be close" is a passive voice. What does it actually mean? I suspect it means they are demanding the store should be closed by someone. Is the word "be close" a verb or a phrase? To be honest, I have lived in the UK for more than 10 years but I haven't heard or seen someone use the above structure in conversation