Analyse - Active/Passive

[Montana]

We have problems with the following:

I write a book.

write = verb - transitive
I = subject
book = object
a= article acting as an adjective, modifying book

What about the passive voice ?

The book is written by me...

is = form of the verb to be = linking verb
written = verbal, ending by -en = adjective modifying book
the = article
by = ??
me = ??

.... or is 'written' the verb and 'is' the helping verb ?
But then 'book' is the subject and that doesn't make sence.....I write and write is a transitive verb....

Thanks for help

[Soup]

The = determiner
book = noun
The book = subject
is = form of the verb BE
written = past participle
is written = passive verb form
by = preposition
me = pronoun
by me = prepositional phrase