molecular biology Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ...

, YccV protein domain is also, alternatively named,

Heat shock protein Heat shock proteins (HSP) are a family of proteins produced by cells in response to exposure to stressful conditions. They were first described in relation to heat shock, but are now known to also be expressed during other stresses including expo ...

HspQ. This entry describes the small

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

from ''

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

'' YccV and its homologs in other

Pseudomonadota Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The ...

. YccV is now described as a hemimethylated DNA binding protein. The model entry describes a protein domain in longer

eukaryotic Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

Function

HspQ is involved in the degradation of certain denaturated proteins, including DnaA, during Heat shock stress. HspQ (YccV like protein domain) is a hemimethylated DNA-binding protein. It has been thought to negatively regulate dnaA

gene expression Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. The ...

when its promoter region is either methylated or hemimethylated. This could occurs through binding of YccV itself to fully or hemimethylated DNA. In addition, studies have identified the ''yccV'' gene as one of three insertion sites in mini-Tn10 which suppress dnaA46 thermosensitivity.

Structure

This protein domain is thought to have a SH3-like barrel structure. Additionally, the structure of a hypothetical protein in this family has been solved and it forms a

beta sheet The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a g ...

structure with a terminating

alpha helix The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues e ...

. HspQ forms a stable homodimer in solution and can form homomultimers consisting of about four monomers. The theoretical

molecular mass The molecular mass (''m'') is the mass of a given molecule: it is measured in daltons (Da or u). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The related quanti ...

of the HspQ protein were calculated to be 11.8 kDa. It is putatively thought that HspQ requires a cofactor to form a functional hetero-oligomeric complex.

References

{{InterPro content, IPR011722 Protein domains