Please note: this site relies heavily on the use of javascript. Without a javascript-enabled browser, this site will not function correctly. Please enable javascript and reload the page, or switch to a different browser.
70  structures 965  species 0  interactions 3476  sequences 319  architectures

Family: SAT (PF16073)

Summary: Starter unit:ACP transacylase in aflatoxin biosynthesis

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Starter unit:ACP transacylase in aflatoxin biosynthesis Provide feedback

SAT is the N-terminal starter unit:ACP transacylase of the aflatoxin biosynthesis pathway. SAT selects the hexanoyl starter unit from a pair of specialised fungal fatty acid synthase subunits (HexA/HexB) and transfers it onto the polyketide synthase A acyl-carrier protein to prime polyketide chain elongation. The family is found in association with PF02801 PF00109 PF00550 PF00975 PF00698.

Literature references

  1. Mayorga ME, Timberlake WE;, Mol Gen Genet. 1992;235:205-212.: The developmentally regulated Aspergillus nidulans wA gene encodes a polypeptide homologous to polyketide and fatty acid synthases. PUBMED:1465094 EPMC:1465094

  2. Feng GH, Leonard TJ;, J Bacteriol. 1995;177:6246-6254.: Characterization of the polyketide synthase gene (pksL1) required for aflatoxin biosynthesis in Aspergillus parasiticus. PUBMED:7592391 EPMC:7592391

  3. Fujii I, Watanabe A, Sankawa U, Ebizuka Y;, Chem Biol. 2001;8:189-197.: Identification of Claisen cyclase domain in fungal polyketide synthase WA, a naphthopyrone synthase of Aspergillus nidulans. PUBMED:11251292 EPMC:11251292

  4. Korman TP, Crawford JM, Labonte JW, Newman AG, Wong J, Townsend CA, Tsai SC;, Proc Natl Acad Sci U S A. 2010;107:6246-6251.: Structure and function of an iterative polyketide synthase thioesterase domain catalyzing Claisen cyclization in aflatoxin biosynthesis. PUBMED:20332208 EPMC:20332208

Internal database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR032088

Nonreducing polyketide synthases (NR-PKSs) are unique among PKSs in their domain structure, notably including a starter unit:acyl-carrier protein (ACP) transacylase (SAT) domain that selects an acyl group as the primer for biosynthesis [ PUBMED:25714897 ]. SAT selects the hexanoyl starter unit from a pair of specialised fungal fatty acid synthase subunits (HexA/HexB) and transfers it onto the polyketide synthase A acyl-carrier protein to prime polyketide chain elongation [ PUBMED:1465094 , PUBMED:7592391 , PUBMED:11251292 , PUBMED:20332208 ].

This entry represents the N-terminal starter unit:ACP transacylase and related domains.

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

Loading domain graphics...

Pfam Clan

This family is a member of clan Patatin (CL0323), which has the following description:

This superfamily of enzymes contains a Ser/Asp catalytic dyad. Members of this superfamily are all serine acylhydrolase enzymes.

The clan contains the following 4 members:

Acyl_transf_1 Patatin PLA2_B SAT


We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...

View options

We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

Representative proteomes UniProt
Jalview View  View  View  View  View  View  View 
HTML View  View           
PP/heatmap 1 View           

1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

Representative proteomes UniProt

Download options

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

Representative proteomes UniProt
Raw Stockholm Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...


This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

Note: You can also download the data file for the tree.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Pfam-B_293 (release 26.0)
Previous IDs: none
Type: Family
Sequence Ontology: SO:0100021
Author: Coggill P
Number in seed: 106
Number in full: 3476
Average length of the domain: 229.60 aa
Average identity of full alignment: 19 %
Average coverage of the sequence by the domain: 10.65 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 57096847 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 22.8 22.8
Trusted cut-off 22.8 22.8
Noise cut-off 22.7 22.7
Model length: 240
Family (HMM) version: 7
Download: download the raw HMM for this family

Species distribution

Sunburst controls


Weight segments by...

Change the size of the sunburst


Colour assignments

Archea Archea Eukaryota Eukaryota
Bacteria Bacteria Other sequences Other sequences
Viruses Viruses Unclassified Unclassified
Viroids Viroids Unclassified sequence Unclassified sequence


Align selected sequences to HMM

Generate a FASTA-format file

Clear selection

This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...

Loading sunburst data...

Tree controls


The tree shows the occurrence of this domain across different species. More...


Please note: for large trees this can take some time. While the tree is loading, you can safely switch away from this tab but if you browse away from the family page entirely, the tree will not be loaded.


For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the SAT domain has been found. There are 70 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

Loading structure mapping...

AlphaFold Structure Predictions

The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.

Protein Predicted structure External Information
A4HV11 View 3D Structure Click here
P07149 View 3D Structure Click here
Q4E0P8 View 3D Structure Click here
Q4E3P7 View 3D Structure Click here
Q5A4W7 View 3D Structure Click here
Q9UUG0 View 3D Structure Click here