Cloning and characterization of corA, a gene encoding a copper-repressible polypeptide in the type I methanotroph, Methylomicrobium albus BG8

In an attempt to identify proteins involved in copper transport in the type I methanotroph Methylomicrobium albus BG8, copper-regulated polypeptides were examined. One major copper-repressible membrane polypeptide of approx. 28500 Da was identified and designated CorA. The gene encoding this polypeptide was isolated and sequenced, and it shared a low identity with a calcium channel protein. An insertion mutation in corA of M. albus BG8 grew very poorly, suggesting that CorA is important for growth of this methanotroph. CorA may be involved in transport of copper and/or other divalent metals ions in M. albus BG8.