Related Experiment Video
Updated: May 22, 2026

Measurement of Heme Synthesis Levels in Mammalian Cells
Published on: July 9, 2015
Bacillus subtilis HmoB is a heme oxygenase with a novel structure
Seonghun Park1, Sarah Choi, Jungwoo Choe
1Department of Life Science, University of Seoul, Seoul, Korea.
Abstract:
Iron availability is limited in the environment and most bacteria have developed a system to acquire iron from host hemoproteins. Heme oxygenase plays an important role by degrading heme group and releasing the essential nutrient iron. The structure of Bacillus subtilis HmoB was determined to 2.0 A resolution. B. subtilis HmoB contains a typical antibiotic biosynthesis monooxygenase (ABM) domain that spans from 71 to 146 residues and belongs to the IsdG family heme oxygenases. Comparison of HmoB and IsdG family proteins showed that the C-terminal region of HmoB has similar sequence and structure to IsdG family proteins and contains conserved critical residues for heme degradation. However, HmoB is distinct from other IsdG family proteins in that HmoB is about 60 amino acids longer in the N-terminus and does not form a dimer whereas previously studied IsdG family heme oxygenases form functional homodimers. Interestingly, the structure of monomeric HmoB resembles the dimeric structure of IsdG family proteins. Hence, B. subtilis HmoB is a heme oxygenase with a novel structural feature.
Related Concept Videos
Gene Families
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Anoxygenic Phototrophic Bacteria
Globular and Fibrous Proteins
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Hemoglobin
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Structure of Porins

