import re


def readSequenceName(line, seq_start):
    """Extract sequence name from given string. Return None if SEQ_NAME_START is not found."""
    if (line[0: len(seq_start)] == seq_start):
        pattern = '(?<={}).*(?=\n)'.format(seq_start)
        name = re.search(pattern, line)
        return name.group(0).strip() if (name is not None) else line[1:-1].strip()
    return None