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387  structures 1682  species 0  interactions 89368  sequences 2108  architectures

Clan: SAM (CL0003)


Sterile Alpha Motif (SAM) domain Add an annotation

SAM domains are found in a diverse set of proteins, which include scaffolding proteins, transcription regulators, translational regulators tyrosine kinases and serine/threonine kinases [1-3]. SAM domains are found in all eukaryotes and some bacteria [3] . Structures of SAM domains reveal a common five helical structure. The SAM domain is involved in a variety of functions. The most widespread function is in domain-domain interactions. The SAM domain performs domain-domain interactions using multifarious arrangements of the SAM domain. More recently, the SAM domain within the Smaug protein has been demonstrated to bind to the Nanos 3' UTR translation control element (Rfam:RF00161) [3]. This clan currently only represents the diverse SAM domain family and does not contain the more divergent SAM/Pointed family (Pfam:PF02198).

This clan contains 12 families and the total number of domains in the clan is 89368. The clan was built by RD Finn.

Literature references

  1. Ponting CP; , Protein Sci 1995;4:1928-1930.: SAM: a novel motif in yeast sterile and Drosophila polyhomeotic proteins. PUBMED:8528090 EPMC:8528090
  2. Schultz J, Ponting CP, Hofmann K, Bork P; , Protein Sci 1997;6:249-253.: SAM as a protein interaction domain involved in developmental regulation. PUBMED:9007998 EPMC:9007998
  3. Kim CA, Bowie JU; , Trends Biochem Sci 2003;28:625-628.: SAM domains: uniform structure, diversity of function. PUBMED:14659692 EPMC:14659692


This clan contains the following 12 member families:


External database links

Domain organisation

Below is a listing of the unique domain organisations or architectures from this clan. More...

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The table below shows the number of occurrences of each domain throughout the sequence database. More...

Pfam family Num. domains Alignment
SAM_1 (PF00536) 49063 (54.9%) View
SAM_2 (PF07647) 26807 (30.0%) View
SAM_PNT (PF02198) 5719 (6.4%) View
SAM_3 (PF18016) 3665 (4.1%) View
NCD1 (PF04904) 1008 (1.1%) View
SAM_KSR1 (PF13543) 989 (1.1%) View
IGR (PF09597) 985 (1.1%) View
SAM_4 (PF18017) 699 (0.8%) View
SAM_LFY (PF01698) 227 (0.3%) View
SAM_Exu (PF18609) 129 (0.1%) View
SAM_DrpA (PF18255) 44 (0.0%) View
SAM_Ste50p (PF09235) 33 (0.0%) View
Total: 12 Total: 89368 Clan alignment

Please note: Clan alignments can be very large and can cause problems for some browsers. Read the note above before viewing.

Family relationships

This diagram shows the relationships between members of this clan. More...

Species distribution

Tree controls


This tree shows the occurrence of the domains in this clan across different species. More...



For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the MSD group, to allow us to map Pfam domains onto UniProt three-dimensional structures. The table below shows the mapping between the Pfam families in this clan, the corresponding UniProt entries, and the region of the three-dimensional structures that are available for that sequence.

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