The Discovery of Vitreoscilla Hemoglobin and Early Studies on Its Biochemical Functions, the Control of Its Expression, and Its Use in Practical Applications

Abstract

In 1986, the surprising identification of a hemoglobin (VHb) in the bacterium Vitreoscilla greatly extended the range of taxa in which this oxygen binding protein functions. Elucidation of many of its biochemical properties and relation to overall cell physiology, as well as the sequence of the gene encoding it and aspects of control of its expression were determined in the following years. In addition, during the early years following its discovery, strategies were developed to use its expression in heterologous microbial hosts to enhance processes of practical usefulness. The VHb discovery also served as the foundation for what has become the fascinatingly rich field of bacterial hemoglobins. VHb's position as the first known bacterial hemoglobin and its extensive use in biotechnological applications, which continue today, make a review of the early studies of its properties and uses an appropriate and interesting topic thirty-five years after its discovery.

Keywords: Vitreoscilla hemoglobin; biotechnological applications; genetically modified organisms; oxygen metabolism.

Figure 1

Transcriptional control region of vgb. Transcription factor binding sites are labeled as described in the preceding paragraph. In addition, there is a region of dyad symmetry (highlighted in yellow) downstream of the -10 region (Pribnow box; highlighted in green) that is probably the binding site for an additional as yet unidentified transcription factor. The ATG translational start codon is highlighted in red.