| HHA | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 solution structure of hemolysin expression modulating protein hha from escherichia coli. ontario centre for structural proteomics target ec0308_1_72; northeast structural genomics target et88 | |||||||||
| Identifiers | |||||||||
| Symbol | HHA | ||||||||
| Pfam | PF05321 | ||||||||
| InterPro | IPR007985 | ||||||||
| SCOP2 | 1ir6 / SCOPe / SUPFAM | ||||||||
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In molecular biology, the haemolysin expression modulating protein family is a family of proteins. This family consists of haemolysin expression modulating protein (Hha) from Escherichia coli and its enterobacterial homologues, such as YmoA from Yersinia enterocolitica , and RmoA encoded on the R100 plasmid. These proteins act as modulators of bacterial gene expression. Members of this family act in conjunction with members of the H-NS family, participating in the thermoregulation of different virulence factors and in plasmid transfer. [1] Hha, along with the chromatin-associated protein H-NS, is involved in the regulation of expression of the toxin alpha-haemolysin in response to osmolarity and temperature. [2] YmoA modulates the expression of various virulence factors, such as Yop proteins and YadA adhesin, in response to temperature. RmoA is a plasmid R100 modulator involved in plasmid transfer. [3] The HHA family of proteins display striking similarity to the oligomerisation domain of the H-NS proteins.