AN1 zinc finger
Encyclopedia
In molecular biology, the AN1-type zinc finger domain, which has a dimetal (zinc)-bound alpha/beta fold
. This domain was first identified as a zinc finger at the C terminus of AN1 SWISSPROT, a ubiquitin-like protein in Xenopus laevis. The AN1-type zinc finger contains six conserved
cysteine
s and two histidines that could potentially coordinate 2 zinc atom
s.
Certain stress-associated proteins (SAP) contain AN1 domain, often in combination with A20 zinc finger domains (SAP8) or C2H2 domains (SAP16). For example, the human protein Znf216 has an A20 zinc-finger at the N terminus and an AN1 zinc-finger at the C terminus, acting to negatively regulate
the NFkappaB activation pathway and to interact
with components of the immune response like RIP, IKKgamma and TRAF6. The interact
of Znf216 with IKK-gamma and RIP is mediated by the A20 zinc-finger domain, while its interaction with TRAF6 is mediated by the AN1 zinc-finger domain; therefore, both zinc-finger domains are involved in regulating the immune
response. The AN1 zinc finger domain is also found in proteins containing a ubiquitin-like domain, which are involved in the ubiquitination pathway. Proteins containing an AN1-type zinc finger include:
AN1-type zinc finger domains are widely present across diverse euryarchaeota
and thaumarchaeota
, where they are often fused to membrane-associated peptidase domains such as the rhomboid family serine peptidase, transglutaminase-like thiol peptidases of the papain
fold, and Zn-dependent metallopeptidases. Archaeal AN1 domains are also linked to transmembrane helices, and domains such as DNAJ and SCP/PR1. These fusions suggest membrane-associated roles for AN1 domain containing proteins in archaea, such as in proteolytic processing of polypeptides and in regulating protein folding or stability. The architectural syntax is remarkably similar to that of the prokaryotic B-box zinc finger
and LIM
domains.
Tertiary structure
In biochemistry and molecular biology, the tertiary structure of a protein or any other macromolecule is its three-dimensional structure, as defined by the atomic coordinates.-Relationship to primary structure:...
. This domain was first identified as a zinc finger at the C terminus of AN1 SWISSPROT, a ubiquitin-like protein in Xenopus laevis. The AN1-type zinc finger contains six conserved
Conserved sequence
In biology, conserved sequences are similar or identical sequences that occur within nucleic acid sequences , protein sequences, protein structures or polymeric carbohydrates across species or within different molecules produced by the same organism...
cysteine
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
s and two histidines that could potentially coordinate 2 zinc atom
Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
s.
Certain stress-associated proteins (SAP) contain AN1 domain, often in combination with A20 zinc finger domains (SAP8) or C2H2 domains (SAP16). For example, the human protein Znf216 has an A20 zinc-finger at the N terminus and an AN1 zinc-finger at the C terminus, acting to negatively regulate
Transcriptional regulation
Transcriptional regulation is the change in gene expression levels by altering transcription rates. -Regulation of transcription:Regulation of transcription controls when transcription occurs and how much RNA is created...
the NFkappaB activation pathway and to interact
Protein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...
with components of the immune response like RIP, IKKgamma and TRAF6. The interact
Protein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...
of Znf216 with IKK-gamma and RIP is mediated by the A20 zinc-finger domain, while its interaction with TRAF6 is mediated by the AN1 zinc-finger domain; therefore, both zinc-finger domains are involved in regulating the immune
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
response. The AN1 zinc finger domain is also found in proteins containing a ubiquitin-like domain, which are involved in the ubiquitination pathway. Proteins containing an AN1-type zinc finger include:
- Ascidian posterior end mark 6 (pem-6) protein .
- HumanHumanHumans are the only living species in the Homo genus...
AWP1 protein (associated with PRK1), which is expressedGene expressionGene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
during early embryogenesisEmbryogenesisEmbryogenesis is the process by which the embryo is formed and develops, until it develops into a fetus.Embryogenesis starts with the fertilization of the ovum by sperm. The fertilized ovum is referred to as a zygote...
.
- Human immunoglobulinAntibodyAn antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
mu binding protein 2 (SMUBP-2), mutations in which cause muscular atrophy with respiratory distress type 1.
AN1-type zinc finger domains are widely present across diverse euryarchaeota
Euryarchaeota
In the taxonomy of microorganisms, the Euryarchaeota are a phylum of the Archaea.The Euryarchaeota include the methanogens, which produce methane and are often found in intestines, the halobacteria, which survive extreme concentrations of salt, and some extremely thermophilic aerobes and anaerobes...
and thaumarchaeota
Thaumarchaeota
In taxonomy, the Thaumarchaeota are a newly-proposed phylum of the Archaea, containing so far four species, Nitrosopumilus maritimus, Cenarchaeum symbiosum, Nitrososphaera viennensis, and Nitrososphaera gargensis...
, where they are often fused to membrane-associated peptidase domains such as the rhomboid family serine peptidase, transglutaminase-like thiol peptidases of the papain
Papain
Papain, also known as papaya proteinase I, is a cysteine protease enzyme present in papaya and mountain papaya .-Papain family:...
fold, and Zn-dependent metallopeptidases. Archaeal AN1 domains are also linked to transmembrane helices, and domains such as DNAJ and SCP/PR1. These fusions suggest membrane-associated roles for AN1 domain containing proteins in archaea, such as in proteolytic processing of polypeptides and in regulating protein folding or stability. The architectural syntax is remarkably similar to that of the prokaryotic B-box zinc finger
B-box zinc finger
In molecular biology the B-box-type zinc finger domain is a short protein domain of around 40 amino acid residues in length. B-box zinc fingers can be divided into two groups, where types 1 and 2 B-box domains differ in their consensus sequence and in the spacing of the 7-8 zinc-binding residues...
and LIM
LIM domain
LIM domains are protein structural domains, composed of two contiguous zinc finger domains, separated by a two-amino acid residue hydrophobic linker. They are named after their initial discovery in the proteins Lin11, Isl-1 & Mec-3. LIM-domain containing proteins have been shown to play roles in...
domains.