Final answer:
Chromatin remodeling complexes possess two subunits and alter the structure of chromatin through chemical modifications of histones and DNA. These modifications can open or close the chromosomal structure to regulate gene transcription.
Step-by-step explanation:
Chromatin remodeling complexes possess two subunits. These complexes are responsible for altering the structure of chromatin, which is composed of DNA and proteins called histones. One example of a chromatin remodeling complex is FACT, which helps remove histones during transcription and replace them afterward. The process of chromatin remodeling involves chemical modifications of histones and DNA, such as acetylation, methylation, and phosphorylation, that can open or close the chromosomal structure to regulate gene transcription.