  Right-angled Artin groups and their subgroups are of great interest because
of their geometric, combinatorial and algorithmic properties. It is convenient
to define these groups using finite simplicial graphs. The isomorphism type of
the group is uniquely determined by the graph. Moreover, many structural
properties of right angled Artin groups can be expressed in terms of their
defining graph.
  In this article we address the question of understanding the structure of a
class of subgroups of right-angled Artin groups in terms of the graph. Bestvina
and Brady, in their seminal work, studied these subgroups (now called
Bestvina-Brady groups or Artin kernels) from a finiteness conditions viewpoint.
Unlike the right-angled Artin groups the isomorphism type of Bestvina-Brady
groups is not uniquely determined by the defining graph. We prove that certain
finitely presented Bestvina-Brady groups can be expressed as an iterated
amalgamated product. Moreover, we show that this amalgamated product can be
read off from the graph defining the ambient right-angled Artin group.
