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The sterile α motif (SAM) domain is a putative protein interaction module present in a wide variety of proteins [1] involved in many biological processes. The SAM domain that spreads over around 70 residues is found in diverse eukaryotic organisms [2]. SAM domains have been shown to homo- and hetero-oligomerize [3], nevertheless with a low-affinity constant [4], and to mediate specific protein-protein interactions.

Structural analyses show that the SAM domain is arranged in a small five-helix bundle with two large interfaces [3,4]. In the case of the SAM domain of EphB2, each of these interfaces is able to form dimers [4]. The presence of these two distinct intermonomers binding surface suggest that SAM could form extended polymeric structures [4].

Some of the proteins in which such a domain is known to exist are listed below.

• Vertebrate Eph receptor protein tyrosine kinases. Involved in developmental regulation.
• Yeast STE11, serine/threonine protein kinase which participates in mating pheromone response pathways.
• Mammalian liprin α. Interacts with LAR transmembrane protein tyrosine phosphatase.
• Mammalian Neurabin actin filament binding protein. Involved in neurite formation.
• Mammalian inositol phosphatase protein Ship2.
• Mammalian SH2 domain-containing leukocyte Protein of 76kDa (SLP-76). Hematopoietic cell specific molecule, critical for T cell development.
• Mammalian ETS translocation variant (ETV) or TEL. Translocations which fuse the SAM domain from ETV to Abl, PDGFB, JAK2 or AML1 have been associated with many human leukemias.
• Drosophila polyhomeotic (ph) and Sex comb on midleg (Scm), member of the Polycomb group genes, implied in the transcriptional repression of homeotic genes.
• Mammalian Polycomb group proteins Rae-28/MPH1 and SCML1. Homologues of drosophila ph and Scm proteins.

We developed a profile that spans the whole domain.

December 2001 / First entry.

PROSITE method (with tools and information) covered by this documentation:

SAM_DOMAIN, PS50105; SAM domain profile  (MATRIX)

Sequences known to belong to this class detected by the profile: ALL Other sequence(s) detected in Swiss-Prot: 1

• Domain architecture view of Swiss-Prot proteins matching PS50105 • Retrieve an alignment of Swiss-Prot true positive hits:   Clustal format, color, condensed view  / Clustal format, color  / Clustal format, plain text  / Fasta format • Retrieve the sequence logo from the alignment • Taxonomic tree view of all Swiss-Prot/TrEMBL entries matching PS50105 • Retrieve a list of all Swiss-Prot/TrEMBL entries matching PS50105 • Scan Swiss-Prot/TrEMBL entries against PS50105 • view ligand binding statistics

Matching PDB structures: 1B0X 1B4F 1F0M 1KW4 ... [ALL]

1	Authors	Schultz J., Ponting C.P., Hofmann K., Bork P.
	Title	SAM as a protein interaction domain involved in developmental regulation.
	Source	Protein Sci. 6:249-253(1997).
	PubMed ID	9007998

2	Authors	Stapleton D., Balan I., Pawson T., Sicheri F.
	Title	The crystal structure of an Eph receptor SAM domain reveals a mechanism for modular dimerization.
	Source	Nat. Struct. Biol. 6:44-49(1999).
	PubMed ID	9886291
	DOI	10.1038/4917

3	Authors	Peterson A.J., Kyba M., Bornemann D., Morgan K., Brock H.W., Simon J.
	Title	A domain shared by the Polycomb group proteins Scm and ph mediates heterotypic and homotypic interactions.
	Source	Mol. Cell. Biol. 17:6683-6692(1997).
	PubMed ID	9343432

4	Authors	Thanos C.D., Goodwill K.E., Bowie J.U.
	Title	Oligomeric structure of the human EphB2 receptor SAM domain.
	Source	Science 283:833-836(1999).
	PubMed ID	9933164

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