Bartonella henselae ''Bartonella henselae'', formerly ''Rochalimæa henselae'', is a bacterium that is the causative agent of cat-scratch disease ( bartonellosis). It primarily infects red blood cells and endothelial cells and is transmitted to humans through scratch ...

'' hypothetical protein 11960 (BH11960) is encoded by the ''BH11960''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. This hypothetical protein is conserved in all ''

Bartonella ''Bartonella'' is a genus of Gram-negative bacteria. It is the only genus in the family Bartonellaceae. Facultative intracellular parasites, ''Bartonella'' species can infect healthy people, but are considered especially important as opportuni ...

'' species whose

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

s have been sequenced to date, and are highlighted in the picture below. ''Bartonella henselae'' is a gram-negative bacterial pathogen of humans and animals. Like other members of the alphaproteobacteria subdivision, ''B. henselae'' is capable of establishing an intracellular lifestyle within eukaryotic cells (3). Infection of immunocompetent humans with ''B. henselae'' results in “cat scratch disease,” a regional lymphadenopathy that is typically associated with wounds of feline origin (12, 22). In most cases, the lymph node lesions are self-limiting and antibiotic therapy is not indicated (32). However, in 5 to 14% of infected individuals, atypical manifestations can occur, including prolonged fever, malaise, fatigue, myalgia, arthralgia, weight loss, splenomegaly, and Parinaud's oculoglandular syndrome (32). In contrast, infection of immunosuppressed humans can result in a variety of severe and life-threatening disease syndromes, such as bacillary angiomatosis, peliosis hepatis, endocarditis, and bacteremia (22). Even in cases of severe disease, antibiotic therapy is often effective, but relapses can occur (32).

Properties

Function

The function of the BH11960 protein is not known, but its function is thought to be involved in

signal transduction Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a biochemical cascade, series of molecular events. Proteins responsible for detecting stimuli are generally termed receptor (biology), rece ...

that regulates aerotolerance in conjunction with the other genes within its cluster. Evidence for such function is: * Presence of a PRKEL

signal peptide A signal peptide (sometimes referred to as signal sequence, targeting signal, localization signal, localization sequence, transit peptide, leader sequence or leader peptide) is a short peptide (usually 16–30 amino acids long) present at the ...

domain at the

N-terminus The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amin ...

of the protein on all

ortholog Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a speci ...

s * Presence of MoxR-AAA family protein in the four-

gene cluster A gene cluster is a group of two or more genes found within an organism's DNA that encode similar peptide, polypeptides or proteins which collectively share a generalized function and are often located within a few thousand base pairs of each othe ...

, which is predicted to serve as a chaperone * Hypothesis: The signal peptide PRKEL allows for the cleavage of the N-terminal aerotolerance regulator, which is released into the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

and folded by the interacting chaperone. This cleaved and modified protein serves as a sensor for

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

concentration changes and may go on to interact with other parts of the cell to induce a response mechanism.

Protein sequence

The importance of this protein lies in the beginning of the sequence, and is represented in the conceptual translation below. This region contains the aerotolerance motif, the transmembrane

hydrophobic In chemistry, hydrophobicity is the chemical property of a molecule (called a hydrophobe) that is seemingly repelled from a mass of water. In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, thu ...

segment highlighted in yellow, and a high-conservation region represented in all studied orthologs. Furthermore, a signal peptide protein is present in this region that allows transport of a protein. Based on

sequence analysis In bioinformatics, sequence analysis is the process of subjecting a DNA, RNA or peptide sequence to any of a wide range of analytical methods to understand its features, function, structure, or evolution. It can be performed on the entire genome ...

performed by PSortB program, this protein is located in the

cytoplasmic membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the cytoplasm, interior of a Cell (biology), cell from the extrac ...

of this

Gram-negative bacterium Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists of ...

and contains a double transmembrane domain.

Gene neighborhood

The four-gene cluster of ''BH11940, BH11950, BH11960'', and ''BH11970'' all produce proteins of unknown function transcribed on the

sense strand In genetics, a sense strand, or coding strand, is the segment within double-stranded DNA that carries the translatable code in the 5′ to 3′ direction, and which is complementary to the antisense strand of DNA, or template strand, which does ...

and encoded by the same promoter. The promoter is ubiquitously conserved in the other'' Bartonella'' species and contains a

TATA box In molecular biology, the TATA box (also called the Goldberg–Hogness box) is a sequence of DNA found in the core promoter region of genes in archaea and eukaryotes. The bacterial homolog of the TATA box is called the Pribnow box which has a ...

. BH11960 is the largest of the four proteins. ''Bartonella henselae'': BH11960. KEGG Database.

Properties

Function

Protein sequence

Gene neighborhood

Homologs

References

Further reading