Systematic method for the detection of potential lambda Cro-like DNA-binding regions in proteins.

We have developed and tested a systematic method for the location and statistical evaluation of potential DNA-binding regions of the lambda Cro type in protein sequences. Using this approach to examine proteins expected to contain such regions, we have been able to compile a statistically homogeneous master set of 37 lambda Cro-like DNA-binding domains. Examination of a protein database revealed other prokaryotic proteins that are similar to this lambda Cro-like group. There are also many DNA-binding proteins that are not found to be significantly similar to the lambda Cro group, consistent with previous suggestions that different types of protein sequence may be able to achieve a similar mode of binding and that there exist other modes of sequence-specific DNA-binding. A useful feature of the method is that it can be applied without a computer.