A Multi-Agent System (MAS) architecture is an organization of coordinated autonomous agents that interact in order to achieve particular, possibly common goals. Considering real-world organizations as an analogy, this paper proposes MAS architectural patterns for information systems which adopt concepts from organizational theories. The patterns are modeled using the i* framework which offers the notions of actor, goal and actor dependency, specified in Formal Tropos and evaluated with respect to a set of software quality attributes, such as predictability or adaptability. We conduct a comparison of organizational and conventional architectures using an e-business information system case study.